RSSCategory: nature

So tempting to anthropomorphize . . .

May 29, 2010 | By | Reply More
So tempting to anthropomorphize . . .

This National Geographic video on cockroaches is fascinating by its own rights, but the quote at the 30 second mark sounded like information that might apply to more than a few of the annoying people in the news:

“The cockroach doesn’t really have a brain per se, but it has instinct and a ferocious desire to survive and reproduce.”

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Your Neandertal Ancestors

May 23, 2010 | By | 3 Replies More
Your Neandertal Ancestors

Scientific convention used to be that modern humans came out of Africa and completely replaced Neandertals (also spelled “Neanderthals”) without interbreeding (for example, see here). New evidence suggests that this hypothesis is incorrect, according to an article by Ann Gibbons called “Close Encounters of the Prehistoric Kind.” The article appears in the May 7, 2010 edition of Science (available online only to subscribers). An international team has now completed the draft sequence of the Neandertal genome, which includes more than 3 billion nucleotides collected from the bones of three female Neandertals who lived in Croatia more than 38,000 years ago.” The analysis described was astoundingly complex, and the consequences of this analysis are startling:

By comparing this composite Neandertal genome with the complete genomes of five living humans from different parts of the world, researchers found that both Europeans and Asians share 1% to 4% of their nuclear DNA with Neandertals. But Africans do not. This suggests that early modern humans interbred with Neandertals after moderns left Africa, but before they spread into Asia and Europe. The evidence showing interbreeding is “incontrovertible,” says paleoanthropologist John Hawks of the University of Wisconsin, Madison, who was not involved in the work. “There’s no other way you can explain this.”

Therefore, many people living outside of Africa carry “a small but significant amount of DNA from these extinct humans.” The consequences of this amazing finding are not lost on anyone:

In a sense, the Neandertals are then not altogether extinct, says lead author Svante Paabo, a paleogeneticist at the Max Planck Institute for evolutionary anthropology in Leipzig Germany, who is surprised to find out he was part Neanderthal. “They live on in some of us.”

The Science article presents the following list of things we now know about Neanderthals:

  • The genomes of modern humans and Neanderthals are 99.84% identical.
  • The scientific data don’t support interbreeding when scientists had most expected it (between 45,000 and 30,000 years ago in Europe).
  • Neanderthals coexisted with modern humans in Europe from 30,000 to 45,000 years ago, and perhaps in the Middle East as early as 80,000 years ago.
  • The amount of admixture is tiny, even among Europeans and Asians, but Neanderthals “are significantly more closely related to non-Africans than Africans on average.
  • The new data fits with the discovery of fossils and stone tools from Israel caves about 80,000 years ago (modern humans and Neanderthals both used these caves and had much in common–they used similar tool-kits and under the same animals). One Neandertal skeleton from the Middle East looked “less robust than Neanderthals in Asia and Europe.
  • Despite the ability to sequence some Neanderthal DNA, there is no possibility of cloning a Neanderthal.
  • “The isolated DNA was in pieces typically about 50 bases long, and there were many missing stretches. Further, despite the story one often hears in the mass media, DNA is not completely responsible for the appearance of an animal. “Chemical modifications to the genome, the way chromosomes arrange in the nucleus, and maternal components in the egg all play a role in translating a genetic blueprint into a viable individual.” None of these are available with regard to Neanderthals. As soon as you substitute another oocyte (e.g., that of a modern human) for that of a Neandertal, you would change the resulting organism.

Despite the fact that there was some interbreeding, it did not happen much. This article quotes evolutionary geneticist Sarah Tishkoff, who asked “Was it a cultural barrier?”

We are cousins with every living thing on planet Earth (including trees and see here), but many of us are both cousins and descendants of Neandertals. Therefore, for those of you who have had ancestors from anywhere outside of Africa (keeping in mind that all of us have ancestors from Africa), you are African and you are Neandertal. I’m planning on having a bit of fun the next time a bureaucratic form requires me to designate my “race.”

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Incredible animal eyes

May 19, 2010 | By | Reply More
Incredible animal eyes

This is your chance to look straight into the incredible eyes of ten types of animals.

Thanks to “Jill” for this link.

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On the monogamy of birds

May 16, 2010 | By | 1 Reply More
On the monogamy of birds

Birds are often reputed to be “monogamous.” Is that true? At Salon, Jed Lipinski discussed the topic with Bernd Heinrich, a renowned naturalist at the University of Vermont, who has recently written “The Nesting Season: Cuckoos, Cuckolds, and the Invention of Monogamy.” Here’s an small excerpt from a larger discussion that touches upon monogamy, “love,” navigation and other topics:

Monogamy among birds is mostly social monogamy, in that they will pair off, but they won’t necessarily be sexually monogamous. Some of them are, of course, but most try not to be, as there are certain advantages to being not monogamous. Monogamy is often forced upon birds because of certain conditions. Mates might be scarce, say, and it’s safer to have a mate around. Or a female needs a mate to keep the offspring alive, to make sure all the courting and mating and nesting hasn’t been a big waste. It takes a lot of resources and help to raise baby birds — so the parents have to have a lot of investment. Social monogamy works for food and protection, especially in the case of geese or birds of prey.

So no, most birds are not monogamous. But monogamy is relative. It differs not only between species but within species as well, and often according to gender. Male birds of paradise are extremely promiscuous, whereas the females are extremely picky. They may only mate once in a breeding cycle, while a male will mate with hundreds of females and at any time. But then there are precocious birds, like ducks and quail, whose females manage to do all the feeding themselves, so a male isn’t really required. . . . And some birds are not at all polyamorous. Ravens, for example, stay in pairs year round. That’s unusual.

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How are Humans Better?

May 8, 2010 | By | 2 Replies More
How are Humans Better?

A new comment thread on an old post discusses the precept that humans are somehow “better” than all other creatures. Sure, as a member of our team, I’d like to think that we are Number One. We’ve even written books attributed to deities that prove that we are the reason for creation, that the octillions of stars in the universe were all put there just for our amusement. Therefore, the book and its believers maintain, we must be the best thing ever. But as an educated human raised by scientists to find first sources and question suppositions, I wonder: “How are we better?”

I have posted before on some of the ways in which our Creator (to use that paradigm) has short changed us. Name any characteristic of which we are proud, and it is easy to find another creature that exceeds our ability. I can only think of one exception: Communicating in persistent symbols.

Unlike cetaceans, birds, fellow primates, and others who communicate fairly precisely with sounds, gestures, or chemical signals, we can detach communication from ourselves and transport or even delay it via layers of uncomprehending media (paper, wires, illiterate couriers, etc). We can create physical objects that abstract ideas from one individual and allow the idea to be absorbed by another individual at a later time. It also allows widely separated groups to share a single culture, at least in part.

This learned behavior is based on our apparently unique ability to abstract in multiple layers and to abstract to a time well beyond the immediate future. We can take an idea to a series of sounds to a series of static symbols, and back again. Our relatively modern ability to reason abstractly (math, science) evolved from our ability to abstract communications. Even Einstein couldn’t hold the proof of E=MC2 in his head.

But is this unique ability really sufficient to declare ourselves overall inherently “better”?

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Another Musing on Our Evolving Ability to Perceive

April 27, 2010 | By | Reply More
Another Musing on Our Evolving Ability to Perceive

I have occasionally ruminated our improved ability to see and understand the universe around us. On this blog, it usually is in terms of comparing the Young Earth view with what we’ve learned in the last few hundred years. Posts such as The Universe is not Specified to Human Scale and My limited vision make the point.

But I’ve started another blog that focuses less on politics and culture, yet found that one of my first posts again addresses the issue of how we’ve improved our vision of the world around us in the last few dozen generations. Please peruse The Object At Hand: Light Lens a Hand, to Help us Understand and see if I am off the beam.

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Fungi

April 18, 2010 | By | Reply More
Fungi

I recently posted on Sir David Attenborough, touting ability to educate us regarding nature. You might have thought, “Well, anyone could give a lively talk on the blue whale, the largest creature to ever live on Earth.” Maybe so. But how many people have ever produced a spellbinding video on fungi? Attenborough and his team are often at their best when presenting species that seem mundane.

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The antipodes of Sir David Attenborough

April 16, 2010 | By | 1 Reply More
The antipodes of Sir David Attenborough

Not everyone has earned the right to burn oodles of carbon-based fuel in order to travel to both the North Pole and the South Pole. Sir David Attenborough has earned that right, based upon his exquisite, inspiring, nature documentaries. Yes, he’s visiting the poles as part of an effort to produce yet another documentary, this one called “Frozen Planet.” Here’s the report from the U.K. times:

In more than half a century of bringing the world into our living rooms, Sir David Attenborough has travelled to pretty much every far-flung spot you can think of. But one inhospitable place, short on wildlife and good excuses for stopping by, remained unexplored by the veteran broadcaster. Now he has finally realised his boyhood ambition to stand on the top of the world.

If you don’t know Sir David Attenborough by name, you’ll like know his face and his upbeat warm-hearted scientifically precise commentary. Here’s one of my favorite clips, where he describes the anatomy of the blue whale:

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Climate: OJ and the Haystack

February 27, 2010 | By | 5 Replies More
Climate: OJ and the Haystack

Why Climate Change Denial Is Like the O.J. Trial is an interesting article. The essence is that the climate denialists are using the same techniques as the OJ defense team: Find anything resembling a needle in a vast haystack of data, then claim that the presence of the needle casts doubt on the character of the haystack itself.

Because there is an overwhelming pile of evidence in support of anthropogenic global warming, there are bound to be occasional pieces of data that can appear to contradict the mass of affirmative information. The pile is overwhelming, especially to non-scientists. Therefore few have the patience to understand the whole thing.

Those who want to spin the counter argument claim that, because the two sides are both represented, therefore the issue is in doubt. And, as in the OJ trial, if there is cause for doubt, then no action is to be taken.

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