turok: evolution

deadbison  asked:

Reptiles generally seem to be very quiet. How noisy do you think Paleozoic wildernesses were?

Since the earliest tetrapods and amniotes in the Late Carboniferous and Early Permian had little-to-no sense of hearing – at best they could detect low-frequency vibrations in air or through the ground – there wouldn’t have been much reason for them to vocalize. (I suppose there’s the possibility of infrasound calls, though, like some modern animals.)

But then better hearing systems started convergently evolving in the various major tetrapod groups around the Early-Mid Permian, so things probably began to get a little noisier. We may never know for certain which animals experimented with that type of communication, since behavior doesn’t fossilize, so it’s an exercise in speculation.

But I doubt it would have been all that quiet anyway, because there was another group of animals around who could have been making noise long before the tetrapods: insects.

independent.co.uk
Why evolution may be smarter than we thought

by Richard A. Watson 

Charles Darwin’s theory of evolution offers an explanation for why biological organisms seem so well designed to live on our planet. This process is typically described as “unintelligent” – based on random variations with no direction. But despite its success, some oppose this theory because they don’t believe living things can evolve in increments. Something as complex as the eye of an animal, they argue, must be the product of an intelligent creator.

Invoking a supernatural creator can ever be a scientifically useful explanation. But what about intelligence that isn’t supernatural? 

Our new results, based on computer modeling, link evolutionary processes to the principles of learning and intelligent problem solving – without involving any higher powers. This suggests that, although evolution may have started off blind, with a couple of billion years of experience it has got smarter.

What is intelligence?

Intelligence can be many things, but sometimes it’s nothing more than looking at a problem from the right angle. Finding an intelligent solution can be just about recognizing that something you assumed to be a constant might be variable (like the orientation of the paper in the image below). It can also be about approaching a problem with the right building blocks.

With good building blocks (for example triangles) it’s easy to find a combination of steps (folds) that solves the problem by incremental improvement (each fold covers more picture). But with bad building blocks (folds that create long thin rectangles) a complete solution is impossible.

(excerpt - click the link for the complete article)

youtube

Evolution - What Darwin Never Knew - NOVA PBS Documentary

Earth teems with a staggering variety of animals, including 9,000 kinds of birds, 28,000 types of fish, and more than 350,000 species of beetles. What explains this explosion of living creatures—1.4 million different species discovered so far, with perhaps another 50 million to go? The source of life’s endless forms was a profound mystery until Charles Darwin brought forth his revolutionary idea of natural selection. But Darwin’s radical insights raised as many questions as they answered. What actually drives evolution and turns one species into another? To what degree do different animals rely on the same genetic toolkit? And how did we evolve?

“What Darwin Never Knew” offers answers to riddles that Darwin couldn’t explain. Breakthroughs in a brand-new science—nicknamed “evo devo"—are linking the enigmas of evolution to another of nature’s great mysteries, the development of the embryo. NOVA takes viewers on a journey from the Galapagos Islands to the Arctic, and from the explosion of animal forms half a billion years ago to the research labs of today. Scientists are finally beginning to crack nature’s biggest secrets at the genetic level. The results are confirming the brilliance of Darwin’s insights while revealing clues to life’s breathtaking diversity in ways the great naturalist could scarcely have imagined.

instagram

OMG it’s a fish with suction cups

Do you ever see really weird and utterly inhuman animals like the big-fin squid, living in utterly inhospitable environments like the deep sea, and experience a weird sort of disorientation when it occurs to you that, given the history of life on Earth, there must have been a point, perhaps hundreds of millions of years ago, when you and it had a common ancestor?

Today’s Lesson - Building our Vocabulary :

* ev·o·lu·tion

noun

  1. the gradual development of something, especially from a simple to a more complex form.

* change

noun

  1. the act or instance of making or becoming different.

* trans·fig·u·ra·tion

noun

  1. a complete change of form or appearance into a more beautiful or spiritual state.

* met·a·mor·pho·sis

noun

  1. a change of the form or nature of a thing or person into a completely different one, by natural or supernatural means.

* trans·for·ma·tion

noun

  1. a thorough or dramatic change in form or appearance.

Don’t forget to study will have a pop quiz tomorrow.

That’s an Eye of a Different Color

Originally posted by sofothings

Originally, everyone had brown eyes, but Danish researchers say that somewhere between 6 and 10,000 years ago, a random genetic mutation tweaked a key molecular switch and the ability to produce brown eyes in some people.

Eye color is dictated, at least in part, by the OCA2 gene, which codes for the P protein involved in the production of melanin, the pigment that gives color to hair, eyes and skin. The actual mutation occurred in a gene next OCA2, which didn’t fully turn off OCA2, but did reduce its ability to promote melanin production.

Eye color — at least for the three most common colors: green, brown and blue — is governed by eight genes. The origins of other colors like gray and hazel are less well understood. Color variation is due to the amount of melanin in the stroma of the iris. Blue eyes have less.

Most babies are born with blue eyes that darken in the first three years as melanin, which isn’t usually present at birth, develops with age.

Heritability of eye color isn’t as simple as you might think. The color of your eyes is not a blend of your parents’ colors, but rather the plucking of chromosomal combinations. Parents with brown eyes are likely to have brown-eyed children, but not always. Darker colors dominate: Brown over green, green over blue.