Evolution, Morphology and Exobiology

...generation to the next? i understand, in principle at least, how the eye might have evolved from something that very slightly resembled an eye, such as a tiny light sensitive area on a single-celled organism; but i'm struggling to imagine how the said organism could have gone from having no eye at all to having the 'proto-eye' in the first place. i believe that this came about due to random genetic mutation; but am i right in thinking it came about in just one generation? isn't the 'proto-eye', the tiny light sensitive area (or whatever the proto-eye may be) itself vastly complex, relatively speaking? and isn't it a lot to believe that this could come about du…

http://www.youtube.com/watch?v=HLK5oIIGdbU&feature=youtube_gdata In this documentary one scientist described how they constructed an RNA viral genome from various other viruses, placed the artificial viral genome in a 'soup' made from lysed human cells and the viral RNA managed to spontaneously assemble itself into viral particles. This opens up the possibility that viruses were the first form of 'life' to evolve on planet Earth and that they subsequently became specialist parasites of the higher life forms when they eventually evolved. Very interesting!

Dear All , A very Happy Darwin Day to all.On this day I would like all of you to introduce with the fascinating world of Darwinian or Evolutionary Medicine. Evolutionary Medicine is all about understanding the evolutionary origin of diseases , understanding the selection forces that have shaped those traits.The field is emerging like anything and due to the constant efforts of the founders evolution will soon be part of Medical Curriculum in USA.I would like to share my brief write up on Evolutionary Medicine with you all : INTRODUCTION: Darwinian Medicine which is the synthesis of two different disciplines of Evolutionary Biology and Medicine is emer…

A creationist has made this statement in a private message to me: "Take a sperm whale fir instance. That creature could not have evolved naturally. They breathe thru a tube that is in no way linked to their mouth. Had they evolved that way, evolution would have ended with the seperated windpipe long before eons of furher evolution provided a whale." Is this a new creationist claim about sperm whales? What is the answer to it? stephanurus

Can the birds singing we perceive as pleasant, melodious, be in birds reality a manifestation as aggressive as dog barking ?

Hi guys, I read this article a couple of days that kind of relates to a situation of me but the issue is I'm not a big science guy. So basically, I'd just like to get some opinions on what I found to be quite an interesting piece. Do you agree with it? Disagree? Why? Your answers would help me tremendously. Thank you in advance. Article: http://www.psychologytoday.com/blog/cupids-poisoned-arrow/201002/straight-men-gay-porn-and-other-brain-map-mysteries

I am making an immortality-based RPG game with some friends. I would also prefer to have scientific basis for future events in game. In the storyline, the city of Atlantis is an incredibly advanced civilization using a massive hovercraft capable of carrying the entire city of Atlantis around the Mediterranean(going to get basis for that later). They also had terraformed a planet around the Sirius stars. They used regular grass and trees added to the planet. This was in 4000 BCE. Would the plants start evolving to better absorb the light of the star? If yes, what color? If they did start evolving, how far would they get by the late 21st century? Lets just say …

Does anyone have any references to this? I'm asking because it seems to me that when our ancestors' hair started to thin out, they had to start carrying their babies. Their hair was too thin for the babies to grip onto. I'm curious because of an article I read on big babies shaping society where they state that no-one seems to know when our babies started to get big. It seems to me that they could get big if they were relying on their own strength to hold on to their mothers. So when our ancestors hair started to thin out, they had to carry their babies and the barrier to big babies was gone. So I was wondering how far back in time this might be.

People cannot agree on how to define "intelligence" and this is a problem with accepting it to explain biological processes. Why can't we simply explain it as an emergent property of memory capable cells that can alter their properties that enable them to counteract the actions of circumstances where they previously were restricted to be enslaved to the changing bioactivity of its environment. It is through experience and trying different alternatives that we can find the best solution to overcome a repetative problem so why isn't this view shared at the molecular level that as a whole perform the same methods of problem solving just like we do at our level?

Does anyone know of an applet or simple program that simulates selection at two loci? I want to play with one that allows different fitnesses for each of the 6 (?) genotypes. I want the a/A genotype to affect the fitness of the b/B genotype, certain simulations I can only change the fitnesses individually.

If humans gradually cultivated various food crops, over hundreds to thousands of years; then could not the same tried-and-true tactic be applied, to cultivating salt-water crops, which could be irrigated, with ocean water ? I.e. take "durum wheat", grow it for hundreds of years, in increasingly saline conditions, and gradually cultivate "beach wheat" ? (Can humans consume sea-weeds ?)

It's something I've been considering lately and wondered if anyone had an answer. Excluding the megafauna which died out relatively recently, the current crop of fauna on the planet are the smallest they've ever been. Why? Going back through all the various ages shows that animals and fish were a lot bigger before than they are now. Pick any era and the waterlife will dwarf everything except a Blue whale while the land predators would find an elephant "snack worthy". Pre reptiles, mammal like reptiles, reptiles and mammals, the rule for over 500 million years was "Big is better". The top of the food chain was always the biggest, meanest carnivore around. So wh…

Why would evolution over design the eye, evolution responds only to need.

Hi in the following pages from a popular text book why in box 23.6 does it tell you that the population/sample size (in this case 200, or simply N), must be doubled in the equation to give 2N, to give p= 180+40/400, where 400 is equal to 2x N? In other words why do we need to double the population size to get the answer? I'm fine with the rest of the equation, so it's just this bit I'm stumped on. It might help if whoever replies to this reads both pages before responding to get an idea of what I'm driving at. This section is somewhat pre-Hardy Weinberg, but I will get around to that in due course once I have got the hang of this. As far as I understa…

I am not expert in this field. In school I had heard that Man was came from monkey. If this is true, then why not now also that process is not running. i.e. Why not now also Monkey is not converting into Man. (Or Monkey is not giving birth to a well knowledge Monkey (Man))

My book provides a little knowledge about this. It says acquired traits can't be inherited. But the theory of evolution is based on it. Isn't it. Haven't homologous organs arise due to change in environment and other factors. I mean to say the once a trait is acquired, it may be inherited in the further generations.

Fascinating. In the article, scroll down to the end to see 3 reconstructions of homo neanderthalensis. look here for the Daily Mail article

Hi, I would really like to hear from anyone with a more indepth knowledge of the search for life on Mars than myself. I am a professional marine biologist with a keen interest in microbiology. I have been extremely puzzled for some time now about the supposed search for life beyond our own planet. Professor Chandra Wickramasinghe is a highly regarded astrobiologist with over 75 publications in Nature alone highlighting his credentials. I have read several of his papers in which he 1- has identified microorganisms in the stratosphere which have to originate from space...the boundary between the troposphere/stratosphere inhibits terrestrial sourced microorganisms achieving …

I've seen this insect on two occasions, months appart. I've been searching for months, and have been unable to identify it. It looks to be a member of protura: twelve segmented hexopods that are classified as insects, but evolutionarily are an intermediate stage between hexopod and isopod. However, it bears no resemblance to any more common protura. Protura are soft-bodied, small creatures that live a few inches underground. This creature, was slightly over a centimeter, hard-bodied, and in both cases were seen on the trunks of beech trees. Likewise, it's anatomy is completely different than that of protura. It's legs had one less segment than protura and are attach…

Dear forum, I was recently challenged, by a creationist, to provide evidence or scientific papers, on how multi-cellular life evolved from a single cell. He also asked for some evidence on the morphology of the first vertebrae. These two topics sound interesting, so If someone could provide some explanations, references or links, containing some answers, I would really appreciate it. Thank you!

This is something that has been on my mind for a while. I have done some research and I cannot find anything that answers my question to my satisfaction.How did they come to be? Did they start with the first seed? If so, how did that seed come about without any other seeds to produce it? If someone could give me a link or something that would be great. I'm also new to the forums..so..hey. I'm 15 and in the 10th grade and want to become a scientist. Thanks.

*Let me preface this post by saying I'm a firm believer in evolution, I'm not trying to "disprove" evolution or anything of that nature* Okay, so usually when evolution is presented alongside cladograms and web-like visual representations of evolution over time, there seems to be an implied consensus that, at some point, there had to have been some original one-celled species from which all subsequent life evolved. However, is it implausible that, perhaps, life arose independently at different geographic locations on the planet? What I'm saying is that say a species of one-celled organism arose in the primordial ooze somewhere in the southern hemisphere. Now what …

There was a comment made on another thread here that UV light cannot penetrate water very well, is this true?

I understand that sabor tooth tigers once roamed in North and South America and became extinct 11000 yrs ago. We now have mountain lions so did these live along side sabor tooth tigers before they became extinct? It seems that many of the large megafauna species appear to have died out around 10000 yrs ago but many of them resemble today's modern species. Could it be possible that they really didn't become extinct but over time with mutations began to look like today's species?

Whilst walking the dogs this morning, pondering the world around me. The thought struck "why have we got kneecaps and not elbowcaps"