Species Spotlight: Desertas Wolf Spider

Name: Desertas Wolf Spider
Scientific Name: Hogna ingens
Conservation status: Critically Endangered
Location: Desertas Islands Portugal
Habitat: Mixed grasslands with exposed rocks and soils
Diet: Predator; invertebrates and lizards

Additional information: The Desertas Wolf Spider is the world's larges wolf spider with a leg span of 3-5 inches. With no mammals on the island this spider is the top predator in its environment. Decline of this spider is caused directly by invasive grasses which root in the crevasses needed for the spider, and other wildlife native to the island, to make homes. Current conservation efforts are underway to move populations of the island's wildlife to areas without the invasive grasses and to remove the invasive grass as well.

Resources:
IUCN Red List
EOL
Animal Arkive

Species Spotlight: Lemur Leaf Frog

Name: Lemur Leaf Frog
Scientific Name: Hylomantis lemur
Conservation status: Critically Endangered (Extirpated from many sites particularly in Costa Rica)
Location: Central America (Panama, Columbia and Costa Rica)
Habitat: Undisturbed Humid Forest
Diet: Unknown though small invertebrates are most likely diet.

Additional information: The Lemur Leaf Frog changes color depending on activity level and time of day. This frog is one of few species that can bask in sunlight for long periods of time without drying out. Pterorhodin pigment in the skin allows it to reflect heat and may add to disease resistance. The resistance of this tiny frog to Chytridiomycosis, a fungal disease that is decimating many amphibian populations, is of great interest to scientists who are involved in amphibian conservation efforts around the world.

Resources:
IUCN Red List
EOL
Animal Arkive

Species Spotlight: Angel Shark

Name: Angelshark, Monkfish, Atlantic Angelshark
Scientific Name: Squatina squatina
Conservation status: Critically Endangered, extirpated from large areas of former range
Location: North Atlantic Ocean, Mediterranean Sea, Black Sea (Formerly North Sea)
Habitat: Coastal waters and outer continental shelf waters with sandy or muddy bottoms
Diet: Carnivore: fish, skates, molluscs, and crustaceans

Additional information: Angelsharks are bottom feeding, nocturnal sharks which spend daylight hours buried in muddy or sandy bottoms with just their eyes exposed. Though not a fish consumed by humans, the biggest threat to the Angelshark is fishing. Their decline is caused because these sharks become by-catch, unused fish caught and often killed, of trawling.

Resources:
IUCN Red List Entry
EOL Entry
Animal Arkive Entry

Species Spotlight: Short-eared Dog

Name: Short-Eared Dog (Short-eared Zorro)
Scientific Name: Atelocynus microtis
Conservation status: Threatened/Endangered
Location: Peruvian Amazon Rainforest
Habitat: Undisturbed Rainforest
Diet: Generalist; fruits, fish, mammals, insects, frogs, crabs, and reptiles

Additional information: The Short-Eared Dog has thick dense fur to stay dry while swimming and in the intense rains within the forest. The dog also has partial interdigit membranes (partial webbing) probably owing to its time spent swimming and fishing. Due to being extremely reclusive the exact numbers in the wild are unknown but it is suspected that there are less than 15,000 left in the wild.

Resources:
IUCN Red List Entry
Animal Arkive Entry
Encyclopedia of Life Entry

Species Spotlight: Sea Pigs

Name: Sea Pig
Scientific Name: Scotoplanes sp.
Conservation status: Unknown but threatened by deep sea trawling
Location: Atlantic, Pacific and Indian Oceans
Habitat: Deep sea >1000m
Diet: detritus and scavenged corpses

Additional information: Sea pigs have a very sensitive sense of smell that they use to locate food. The appendages, including those coming from the animal's back, are legs. Sea pigs are echinoderms, related to starfish and sea urchins, and are a type of sea cucumber. These animals have been cited as a possible source for figuring out the life style of the fossil Hallucigenia from the Burgess Shale deposits.

Resources:
Encyclopedia of Life Entry
Facts from WIRED Magazine
From Echinoblog

Species Spotlight: Fossa

Name: Fossa

Scientific Name: Cryptoprocta ferox

Conservation status: Endangered

Location: Madagascar

Habitat: Dense forests and woodlands

Diet: Carnivore; lemurs, rodents, frogs, lizards and birds.

Additional information: Despite its feline appearance, including retractable claws, the Fossa is the largest member of the mongoose family that can grow to over 2 feet long and close to 30 lbs. The Fossa specializes in hunting lemurs. Due to its forest habitat requirements this species has seen a population drop of 30% over the past 20 years as Madagascar rainforest is cleared for agriculture and by logging. It is also often targeted by locals for eradication because it will prey on domestic fowl.

Resources

IUCN Red List Entry

Animal Arkive Entry

Species Spotlight: Pink Fairy Armadillo

Name: Pink Fairy Armadillo
Scientific Name: Chlamyphorus truncatus
Conservation status: Unknown/Data deficient
Location: Argentina
Habitat: Desert, and dry, sandy grasslands
Diet: Worms, insects, snails and grasses

Additional information: The smallest of the armadillo species, measuring 3-4 inches long on average. Nicknamed the "sand swimmer" for its extraordinary speed and efficiency when it comes to burrowing. Listed as Data Deficient; little is known about its population status, ecology or requirements. Due to its capture for black market pet trade and the fact that it has a poor survival rate in captivity it is a priority species for future assessment studies.

Resources:
IUCN Red List Entry
Animal Arkive Entry

Species Spotlight: Maui hesperomannia

Common Name: Maui hesperomannia
Scientific Name: Hesperomannia arbuscula
Status: Critically Endangered
Type of plant: Shrubby tree
Habitat: Lowland rainforests
Range: Maui and Oahu

Additional information: This distant relative of the Magnolia resembles a more familiar plant, rhododendrons, in growth and shape. Only 25 individuals are thought to remain of this beautiful plant. The biggest threats come from feral pigs, introduced rats, invasive plant species, trampling by humans and human collection of specimens. Several botanical gardens are propagating this plant to help with species survival.
Animal Arkive
EOL
IUCN Red List

New Resources - Let's learn MATHS!!

I will still be answering questions as I receive them, however, I have been asked to add something additional. As we move forward I will be adding resources for science learning in the online environment. These will not, for the most part be sites for taking classes but rather sites for learning aids or for fun science learning.

The first request was for mathematics resources, so here are some of my favorites...

Math Warehouse
This is an interactive site for students, teachers and just about anyone who needs to brush up on math concepts. The site is easy to navigate by math type or searching.

Math is Fun
Another site that covers a wide range of math topics from geometry and algebra. Each topic has a ton of images, great definitions and activities to reinforce the information. The site is easy to understand and breaks all the topics down to easy to understand and manage topics.

Math.com 
This is a self tutoring site for Kindergarten to Calculus and some other advanced topics in math. The site includes things like study tips and test prep guides as well as practice problems. It is a great all around source for learning new or brushing up on older math knowledge.

Cool Math Games
Learn basic math concepts with some fun flash games.

Numberphile
A great youtube channel that tackles complicated and interesting math topics through series of weekly videos. Also the Numberphile 2 Channel which covers many of the topics more in-depth than the main channel.

TecMath
A youtube channel that shows tricks and tips for doing math and remembering mathematical information.

Mathantics
Youtube channel to review or learn various math principles.

3Blue1Brown
Ever wanted to learn math as entertainment? Then this is the youtube channel for you. Sadly it has been almost a month since they uploaded their last video.

Mathologer
A really fun math channel that explore theories and properties with visual demonstrations.

ViHart
A really fun channel that explores math concepts with humor and a free form style that one might imagine a journal being written in. Bonus for the riotously funny sketches and images that go with it. (And it covers some other topics too.)

#29 Is it a coincidence that a female's menstrual cycle is equivalent to the moon's orbital period? Are they connected?

This question comes from Tom S. via the blog.

There are a couple things in this question I want to address. First, if it is a coincidence it is not connected. In science there is a concept of "coincidence or correlation does not imply causation or connection". There is a great humor blog called Spurious Correlations that shows that you can make anything correlate.

That aside, the second and more important concept to address is that this assumes all women have the same menstrual cycle. This is an assumption that is often made but not reality. What it comes down to is that this concept is comparing two estimates as if they are real, measured and accurate numbers. I think this is what we will address, as well as the moon cycle itself.

How long does it take the moon to orbit the Earth?

This in itself is a complicated question because the moon phase appearance is influenced by the moon orbiting the Earth and the Earth orbiting the Sun. The moon orbits the Earth in just over 27 days. However, it is 29 and a half days for the moon to pass through all the phases. (Discussion of Lunar cycles) Which of these would we consider the moon cycle? The 28 days we usually hear is an average of these two time lengths. (We will see in this discussion that a lot of common knowledge on the subject is based in comparing multiple averages and not real numbers.) In truth, every common calender lists the moon cycle as 29.5 days and not the 28 that we associate with the menstrual cycle. You can read about all the calender relations and much more on lunar cycles here.

The female cycle

There is a huge misnomer in common knowledge that a female cycle is fixed at a certain number of days. This is not true. The length of a female cycle changes for many reasons and may change over a woman's life time. To this discussion I think it is important to look at some of the many things that can change the length of a woman's menstrual cycle. Most women fall in a 21 to 35 day cycle while it is not uncommon for women to exceed the 35 days as well. This time period is for the average woman without the influence of medications, such as birth control, or other influences from the list we will be discussing below. Of those 21-35+ days, 2-7 days is spent bleeding. This is the numbers for adults. However, for teens and pre-teens the range is even greater and may be 21-45 days or longer between periods.

Circadian Rhythm and Sleep

Our natural internal rhythms can alter the frequency and duration of a menstrual cycle. Sleeping excessively or not enough can have an impact on menstrual cycle length. Chronic insomnia can affect the length of a menstrual cycle causing a woman's normal cycle to be longer than the 35 days at the upper end of the average. Melatonin levels can change the length of a cycle too. This is important because of the use of over-the-counter melatonin for sleep which makes this influence more common than in the past. There is plenty of research that shows sleep rhythms can have such an effect on the cycle that it can impact fertility.
A research paper about circadian rhythms and menstraul cycle

Eating and Weight

The amount one eats can impact length of menstrual cycle. Decrease in food due to starvation, be it external such as famine or internal such as anorexia or bulimia, can  decrease the frequency of menstrual cycles. In some cases lack of food can eliminate the menstrual cycle completely. On the other side, over eating and being obese can decrease frequency of menstrual cycles. Types and quality of food can also affect menstrual cycle duration. Other things such as alcohol and caffeine consumption can alter period length.
Research paper weight and sex-hormones
Research on anovulation
Bariatric surgery and menstrual/fertility issues

Exercise

Intense exercise can alter fertility and menstrual cycles as well. Called exercised induced Amenorrhea, this is a complete lack of menstrual cycle but it can also be a decrease in frequency.

Medications and Illness

A large number of illnesses can affect period duration. Everything from anemia to uterine cancer can alter menstrual cycles. Medications can also affect the duration and intensity of menstrual cycles. Many mood stabilizing medications such as anti-depressants can increase or decrease the length of menstrual cycles.
Diseases and conditions that are effected by or affect menstrual cycles.

Age

Young and old women both experience irregular menstrual cycle lengths. Between the ages of 25 and 40 women experience the most regularity in periods. Prior to the age of 25 menstrual cycle irregularity is related to the hormone imbalances related to sexual maturity and development. After 40 the irregularity is due to peri-menopause.

Stress Levels

High stress levels can trigger less frequent or erratic menstrual cycles. At the root of this is the body mechanism, the same one in play with starvation, that signals that this is a poor time to conceive a child.This body stimulus can reduce the amount of menstrual cycles, which reduces the number of ovulations or chances to become pregnant.
Stress and Menstration
Affects of stress on women's health
Research paper on job stress and menstrual length

Other considerations.

The often cited study by Winnifred B. Cutler in 1980 that is used as proof that women's cycles are related to the moon doesn't prove anything. In the study it was shown that 40% of the studied women had a period start within 2 weeks of the full moon, i.e. within half a month of the full moon. The two week time frame is very large considering this is half of the entire moon cycle. The other thing to consider is most of the women, 60%, showed no relationship at all with time of period and full moon.

More reading:

Exercise and weight and menstrual cycles
Missed periods, exercise and osteoporosis
Stress, ovulation and bone health
List of everyday things that can affect periods.
Causes of Amenorrhea
The moon and activities
Moon cycle length and estrus length in multiple animals.
Do women who live together actually synchronize?

#28 Book Review: Undeniable: Evolution and the Science of Creation

Undeniable: Evolution and the Science of Creation

By Bill Nye

What is this book about?
This book, despite the title, is actually focused on the basic research, discoveries and theories that support evolution. It discusses the benefits that have come from the study of evolution and the history of the concept.

What I love about this book...

It is written in a very relaxed and informative. It is very easy to read and is written very much like the Bill Nye the Science Guy TV show. The book covers some very in-depth and complex science concepts in a way that anyone can enjoy and understand. It has a lot of humor as well as seriousness. Even as someone who knows the science background there was enough history and related information to keep it interesting.

What could have been better?
This is a book that I read in print and kind of wish I would have listened to the audiobook. I feel like Bill Nye's exuberance that comes through in his voice would have made the book even more enjoyable. I do feel like the title might keep people from reading this book. There isn't much in this book about creationism at all which some people might think given the title.

Question #27 What is the importance of herd immunity?

From Linda on Facebook.

Before we talk about the importance of herd immunity we should define it. Herd immunity is sometimes called community immunity. I think herd immunity is most easily defined through an example.

Let's imagine two communities of 100 individuals. 

Community A Most of the individuals have had vaccinations (90) and there are 10 people who are either too young or too immune compromised to be vaccinated. So in this community 90% of people have vaccinations and 10% cannot receive them.

Community B Few individuals have had vaccinations (10) and there are also 10 people in this community that are either too young or too immune compromised to receive vaccinations. In this community 10% have vaccinations, 10% are unable to get vaccinations and 80% are unvaccinated, meaning they have no immunity.

Now, let's imagine the virus that the vaccination is for comes into contact with these two communities. 

In community A, 90% of people who come into contact with the virus are not effected by it because their immune system has antibodies. These 90% of individuals also do not become carriers, meaning once they come in contact with the virus they do not carry the virus off to infect other people. This means that 9 out of 10 times the virus tries to invade this community it is ineffective because of the immunity. Most of the herd/community is immune to the virus so those who don't have the immunity are unlikely to contract it.

In community B, 10% of the people who come in contact with the virus have immunity and do not become sick or carriers. However, 80%, or 8 out of 10, of individuals do come down with the sickness and carry the virus into the community to infect others. That means the 10% unable to be vaccinated have an 80% chance of catching this virus. Those most susceptible to the virus are highly likely to come in contact with a community member who is carrying the virus.

This is the basis of herd immunity, the more of the herd that is immune the more safeguard there is for those who are unable to receive vaccinations or may be in serious danger from becoming sick, such as the young, those with immunodeficiency diseases, or undergoing chemotherapy. Herd immunity works on small scales; a single family with a new baby or a sick elder; or a community as large as an entire city, state, country or the broader world. Herd immunity is important to stop the spread of a disease from one individual to another and is a major force in preventing epidemics and pandemics.

What percentage (R0) of the population must be vaccinated to provide herd immunity?

This is a very tricky question and involves several variables. One major variable is how contagious the virus or bacteria, or how fast it spreads. The more contagious the disease the higher the percentage of people needed to provide herd immunity. The interaction and travel patterns of the community matters to this as well. With modern travel, such as cars and airplanes, someone carrying a virus can travel much farther in a single day. This means that the herd immunity of the home population and the destination population are both equally important when it comes to a carrier. In general, the higher the percentage who are vaccinated, the better the herd immunity.(Check out the link in the more information section for an article about how this is calculated)

Why are vaccinations important to herd immunity?

Vaccinations provide a few important things. First, immunizations create a record of who has immunity. This information is important during an outbreak and also allows officials to track down patient Zero. (Patient Zero is a term for the person who initially brings a disease into a community. Knowing patient zero can allow officials to track who they have been in contact and who might have contracted the illness.) Secondly, vaccinations allow the individual and the medical professionals to know that an individual, or group of individuals, is immune to a specific strain of a disease. Perhaps the most important aspect of herd immunity through vaccinations is that it allows a large portion of the population to become immune without having to contract the disease. This is a particularly important benefit when the disease is debilitating or has a high rate of death, such as polio. A final importance, at least to those who have and love pets, is that some diseases are zoonotic, meaning they can be transmitted between people and animals. Having a pet and/or person vaccinated against a zoonotic disease protects the human population, the pet population, and in some cases populations of food animals.A great example of a pet vaccination that provides safety to both the pet and the humans who love them is the rabies vaccination.

More information:
Research paper on the benefits of herd immunity in Meningitis
 PBS page that discusses how to calculate percentages required for herd immunity to be effective as well as other related topics.
CDC discussion of herd immunity
Series of interactive animations to show visually the impact of herd immunity vs no herd immunity

Free Courses online that cover immunity and health
An Introduction to Global Health
An Introduction to Population Health
Epidemiology: The Basic Science of Public Health
Epidemics, Pandemics, and Outbreaks

Question #26 Who is longest fish in the whole Universe?

Submitted by nasimul via email

There are two ways of looking at this question. First what is the longest fish that has ever lived and the second being what is the longest extant, i.e. currently living, fish. I will answer both of these questions. The interesting thing about most of these giant fish is that they feed on the smallest of ocean dwellers, plankton.

Longest Extant Bony Fish. - Regalecus glesne

The longest extant bony fish is my favorite fish, the Oarfish. The oarfish is a deep sea fish that lives at the depths of 600 feet (200m) in the Atlantic Ocean and Mediterranean Sea.(Though there have been seen in the Pacific Ocean) These fish are so long and strange looking that they are the sources of quite a few of the world's sea serpent myths. These long, slender, and serpentine fish can grow to 50 feet long (15 m) ad weigh over 600 lbs (272 kg).

Largest Extant Cartilaginous Fish  - Rhincodon typus

Not to be alone, currently the record of largest extant fish bounces back and forth between the Oarfish and the Whale Shark. As larger and larger specimens of both of these species are recorded it seems that they may have a tie for the largest fish in the sea.  The largest whale shark to date has been 41.5 feet long and 2.35 tons. These giants live in tropical waters where they filter feed on plankton.

 

Largest fish to ever live - Leedsichthys

This extinct fish may have grown larger than the oarfish. Their length was at least 54 feet and may have grown to be even larger. The largest specimen to date has been 72 feet. These bony fish ate plankton that they filtered from the water much like modern day baleen whales, such as the humpback and right whale.  Leedsichthys lived about 150 million years ago, in the early Jurassic Period when dinosaurs were just showing up on the planet.

 From Chased by Sea Monsters:




More information:
More about the Oarfish
Giants of the Sea