Biologist Answers More Biology Questions From Twitter

@OStoned asks, Bro, how is coral an animal?

What's hits j?

Oh, hitting a joint.

So do you want me to say that?

I'm biologist and author Thor Hanson.

Today, I'll be answering your questions from Twitter.

This is Biology Support part two.

[upbeat music]

@PaulRizzo28 asks, #WildEarth do ostriches

really hide their head in the sand?

No, they don't.

It's a myth and no one's quite sure

where that myth came from.

Although, there are certain displays that male ostriches do

during the breeding season where they get down on the ground

and move their heads back and forth and sway

and show off their amazing plumage.

But at no point do they actually

burry their head in the sand.

@icedancerben aks, How do ticks latch on like that?

Well, if you ever get a chance to look closely

at the mouth of a tick, you will be horrified.

They have two little knife like blades

that cut into the flesh and then something

that looks like a tongue, but with all of these barbs on it,

so that when it's inserted,

it cannot be pulled out easily again

and that's just the beginning.

The saliva of ticks includes an anticoagulant

that prevents your blood from clotting.

It includes something to make your blood vessels expand

so that more blood comes to the wound.

And it includes an analgesic, a pain killer,

so that you won't feel a thing.

In fact, the ability of ticks

through their bite and their saliva to overcome our defenses

is one of the reasons that so many diseases

like Lymes disease take advantage of ticks.

They are free loaders relying on the ways

that ticks overcome our defenses

and giving those disease organisms a free entry point

into our bodies.

@AmandaSmithSays, Weird biology question.

Do female mammals get a monthly period?

Or do they just get their periods during the mating season?

The answer is that most female mammals

don't get a period at all.

Menstruation, as we know it in homo-sapiens,

is actually very rare in mammals.

Known just from our species and mostly a few other primates.

And they have a cycle that is called estrus,

which can occur every few days in something like a mouse,

or only a few times a year in many of the larger mammals.

They reabsorb the uterine lining rather than shedding it.

@ftblkwmn asks, Does salt really hurt slugs?

Or is that some cartoon shit?

The answer is it really does hurt the slugs.

If you've ever left a salt shaker out

in a humid environment,

you might have noticed that the salt tends to cake up.

That's because salt is very good at absorbing moisture.

And a slug is more or less like a bag of moisture.

So when you salt a slug, the salt dehydrates the slug,

it draws the water out of the skin,

desiccates the slug and kills it.

@HarryWhoover asks, How do murder hornets work?

Do you just give them a list?

So murder hornets have been in the headlines lately

because they are recently arrived in North America.

They are an Asian species, the Asian giant hornet.

And it's believed that they jumped over the Pacific Ocean,

not on their own wings,

but in shipping containers arriving probably

in the port of Vancouver, in British Columbia.

And over the border into the state of Washington.

Well, I happen to have murder hornets right here

in all three phases of their life cycle.

The larvae, the pupae, and the adult.

And we focus most of our attention on the adult

because they're large and scary and have a potent sting,

but in a lot of ways

the trouble starts right here with the larvae.

Because if you can imagine a nest,

a colony of murder hornets with hundreds,

or even thousands of these giant grubs

that are hungry all the time,

it's quite a job for the adults.

And they have developed then a particular strategy

that sets them apart.

They target other social insects

like honeybees or paper wasps,

where if they can succeed in overcoming the colony,

they can find a huge amount of food in one place

to take back to feed to the kids back home.

And that strategy has led them to evolve

this large body size with extremely thick exoskeletons

that can withstand the stingers of the insects

that they're attacking.

So, it really is the responsibility of the adults

to feed the young that has driven their evolution

to be so large and scary in the first place.

@JakeVig asks, What's the weirdest animal?

Platypus excluded.

In biology, We don't necessarily think

about animals as weird,

but we are very interested in the marvelous adaptations

that some animals come up with.

So when we're talking about finding strange ones,

we look in extreme places.

My favorite of these weird environments and odd creatures

has to do with the carcasses of whales.

What we call whale falls,

when they sink to the bottom of the ocean

and create their own little ecosystem.

And there are zombie worms that have evolved

specifically to devour the bones of whales,

but they do so without mouths.

They excrete an acid that dissolves the bones of the whales

and they live alongside bacteria

that help transfer the nutrition from those dissolved bones

inside the worm itself.

So, in biology, if you want to find strange creatures,

look in strange places.

@OStoned asks, Bro, how is coral an animal? Hits j.

So a coral is an animal, a tiny animal,

with a mouth and with little tentacles

that reach out and grab food from the water,

not all together dissimilar from something like a barnacle.

But where a barnacle lives alone,

corals live in colonies of thousands

of clone-like individuals.

And they take on elaborate shapes

to get themselves up off the ocean floor

into the water column to feed,

but also, to allow the dinoflagellates or algae

that live alongside them to photosynthesize

because the little coral polyps get some nutrition

from the photosynthesis going on in their symbiotic algae.

And that's why many corals take on shapes

that resemble plants.

They're trying to increase the surface area

of their structures so that more photosynthesis

can take place.

And we all have a connection, a surprising connection,

to corals and other shell-making creatures in everyday life.

That's because when their shells break down in the ocean,

particularly in shallow tropical seas

where corals and shell-makers are very, very common,

those sediments harden into limestone.

Which we then later mine to produce cement.

And you can track the course of the shell into the cement

by looking for something called calcium carbonate,

which is the main component of shells

and is found in cement as well.

And you can do so with the addition of hydrochloric acid,

which dissolves that calcium carbonate

producing bubbles of carbon dioxide alongside water.

You can see it in the shell

and you can see it in the cement.

Which means of course, that surprisingly enough,

even in our most built in environments,

we're never really that far from a tropical beach.

@KingKaiju8 asks, #Botony #Biology,

Question for all you plant-centric scientists.

Are there any plants with pleasant common names,

but are instead deadly and or toxic?

The answer is yes and I happen to have the seeds

of one of them right here.

These come from a plant pleasantly enough called

the rosary pea.

And it is in the pea family

and they do use these beautiful black and red seeds

to make rosaries and other forms of jewelry.

But the plant is deadly, deadly toxic.

One seed well chewed is enough to kill a person.

@FaunaGrace asks, Do bulls really hate the color red?

The answer is no, they don't hate the color red.

They can't even see the color red.

You could irritate a bull with a polka dot cape

or a brown cape just as easily.

It is the motion that attracts their attention.

The color red was chosen, one,

because it's showy and it may please the audience,

and two, for a more grizzly purpose,

it hides the blood stains that the injured bull might leave

as it passes underneath.

@JPetrou97 asks, For viruses,

the goal is to continue to spread and manufacture

by utilizing a host. What good is a dead host?

Therefore, is there any reason to believe

COVID would mutate to be more deadly

as opposed to more transmissible, but less deadly?

Well, the short answer is yes,

we expect that a virus over its history in a population

will eventually mutate into something less deadly

and very transmissible because that is in the best interest

of the virus itself.

But of course, mutations are random events.

So there is still the chance that COVID or other viruses,

particularly when they're new in a population

to have a mutation that produces something more severe.

@Hobvicore asks, Are the cells of an elephant

bigger than the cells of a rat? Explain why or why not.

Well, the answer is no.

There are limits to how big a cell can grow,

whether it's in a rat or an elephant.

Because cells, like any living thing,

they need fuel and they produce waste.

And the way that they get those things

into and out of the cell

is through a process called diffusion.

So if you get too large of a cell,

it becomes inefficient and you can't get the stuff

all the way into the middle of the cell

where it is required.

Interestingly enough, one of the only creatures out there

to get around that limitation of diffusion,

is a particular group of very small organisms,

certain bacteria, that have developed bubbles, if you will,

within the cell called vacuoles

that push all of the essential parts of the cell

closer to that cell wall.

Allowing the cell to grow larger and still be serviced

by the process of diffusion from the outside.

So are the cells of an elephant larger

than the cells of a rat?

The answer is no.

@IslandFanGirl1 asks,

Why will a mother bird abandon its chick

if touched by a human?

Well, the answer is they don't. That's a common myth.

Many studies that use tagging of young birds

rely on going to the nest, applying a small tag to the bird,

and then of course, returning it to the nest

and allowing the mother to raise that bird to maturity.

Now that's not to say we should all go out

and start touching baby birds,

but it does point out that most birds

have a very high loyalty to their eggs and to their chicks

while they're raising them.

And even if those nests are disturbed

by us or by a potential predator or what have you,

the adult birds will most likely return and finish the job.

@alamedamark asks, Question for biologists.

Is there any other species that attacks its own species

as frequently as humans do?

The answer is yes, there are all sorts of species

that attack members of their own species in nature.

Consider the praying mantis

where the female will happily decapitate the male

after population and eat the male

to provide a free meal and more energy

for raising up her brood of eggs.

Or consider lingcods and various fishes

that are perfectly happy to eat smaller individuals

of their own species.

They choose their meals by size,

not by whether or not they're related.

But if we want to look for examples

of planned attacks in nature,

it helps to look at one of our closest relatives,

the chimpanzees who are known to organize raids

from one neighboring band to another neighboring band

with the express purpose of finding isolated individuals

and attacking them and even killing them.

That is a grizzly behavior,

but one that we can look upon with some familiarity

because we see it in our own species.

@Elmostwitter asks, Question for biologists.

Is it possible to bring back extinct species?

If so, how? #Bilogoy.

Extinction really is, for the most part, forever.

That said, there are efforts underway

to bring back certain species that have DNA preserved

in a frozen state.

For example, woolly mammoths where there is at least

some recognizable DNA in the carcasses

that are still available in the frozen tundras

of the far north.

So there is some sort of Jurassic Park

style biology going on to bring back some of those species.

However, there are situations where species

go extinct in the wild, but then can be reintroduced later

after some sort of captive breeding project.

One of the most exciting to entomologists, at least,

examples of this has to do with a creature

called the tree lobster.

A giant stick insect found on Lord Howe Island

in the Tasman Sea and considered extinct for over a century

until a few dozen individuals were found

eeking out a tiny existence on a rocky spire

just off the coast.

They were gathered, they were bred in captivity,

and they now number in the thousands.

And biologists are just waiting for the day

they can reintroduce them to Lord Howe Island

after they eradicate the rats

that got them into trouble in the first place.

@YourFriendTina asks, Why is wildlife conservation,

as a career, kind of looking sexy rn?

Well, is it looking sexy?

That's great news for wildlife conservationists.

The field of wildlife conservation

may appear sexy or may appear booming to you right now

because it's more important than ever before.

As wild areas and natural areas and biodiversity diminish,

the role of conserving what's left

becomes more and more important.

And we do have some success stories to look to

and to inspire us as well.

Consider, for example, the California condor.

Nearly extinct decades ago.

So rare that the last few individuals

were trapped from the wild, bread in captivity for decades,

and are now slowly being released

back into their former habitat.

Flying over Northern California,

places where there huge wingspans

have been missing for decades.

So those are all the questions we have for today.

A wonderful mixture of questions, by the way.

Thank you for watching Biology Support.