On the evolution of ageing

Had a very interesting discussion with the class on ageing and immortality.

Found this Nature article (Kirkwood and Austad 2000 Why do we age? Nature 408 (9) 233-238) and also this wiki entry on the evolution of ageing.

Why_do_we_age.

http://en.wikipedia.org/wiki/Evolution_of_ageing

Darwinian Left – Blog on evolutionary adaptations of local flora and fuana

Very neat and nice blog on local flora and fauna. Much needed here.

http://darwinianleft.blogspot.com/

Sci Am: Good mutations: Stalking evolution through genetic mutation in plants By Katherine Harmon

Good mutations: Stalking evolution through genetic mutation in plants
By Katherine Harmon

Thale cress (Arabidopsis thaliana) has one of the smallest genomes in the plant kingdom and is a laboratory darling around the world owing to its relatively short code. First sequenced in 2000, the humble weed has only 120 million base pairs in its genome (humans, by contrast have about 2.9 billion), but it still packs plenty of genetic mystique.

A new study has uncovered the rate of the plant’s spontaneous mutations as they happen across generations—a finding that could help illuminate the evolutionary history of plants and selective breeding efforts in the future.

“While the long-term effects of genome mutations are quite well understood, we did not know how often new mutations arise in the first place,” Detlef Weigel, director at the Max Planck Institute in Germany, and coauthor of the study which appeared online Thursday in Science, said in a prepared statement.

The group studied genetic changes of five different plant lines across 30 generations. After carefully comparing each full genome, they found that only about 20 base pairs had mutated in each line.

“The probability that any letter of the genome changes in a single generation is thus about one in 140 million,” Michael Lynch of the Department of Biology at Indiana University in Bloomington and study collaborator, said in a statement.

Locating these small numbers required some high-powered sequencing. “To ferret out where the genome had changed was only possible because of new methods that allowed us to screen the entire genome with high precision and in very short time,” Weigel said. Despite the new sequencing capabilities, the team still rechecked each letter’s position 30 times to make sure suspected mutations were being accurately assessed. As high-throughput sequencing becomes more widely available, researchers should be able to conduct more mutation-rate studies. One ongoing study at Michigan State University that is tracking evolutionary change in E. coli, for example, has analyzed hundreds of mutations across 40,000 generations of the bacteria.

The new findings might prove to be more than a simple gee-whiz figure. This study revealed that mutations were occurring at about the same rate across the full genome—not just in specific parts. This might help explain why efforts to keep some plants at bay with single-gene-targeting herbicides are often only briefly successful. It should also hearten researchers who are searching for ways to improve crops—making them more drought-tolerant or better producers—to know that these mutations are likely already occurring. But to truly expedite strategic breeding for many crops, full genome sequencing, as was recently accomplished for corn, will be crucial to giving horticulturalists a genetic map to different traits.

The group has also been able to use the findings to peer back into Arabidopsis thaliana ’s genetic past. Previously, researchers had speculated that it and its closest relative, Arabidopsis lyrata, had split about five million years ago. The new genetic data suggests a divergence at least 20 million years ago.

Although these results are from a lowly mustard relative, the data might also have implications for understanding human genetic change.

“If you apply our findings to humans, then each of us will have on the order of 60 new mutations that were not present in our parents,” Weigel said. A study published in Current Biology in August estimated that each individual had something more along the lines of 100 to 200 new mutations. Whatever the exact number, the modest mutation rate can have a big impact when spread across some six billion individuals. And even though natural selection usually appears to work on a relatively slow timescale, with so many mutations, nature can be assaying new combinations all the time. “Everything that is genetically possible is being tested in a very short period,” Lynch said.

Image courtesy of Wikimedia Commons/Suisetz

Octopus Camouflage

Amazing sequence

This was filmed by David Gallo

Feeding birds ‘changes evolution’

Feeding birds ‘changes evolution’
By Victoria Gill
Science reporter, BBC News
Bird-feeders, hung in many a garden, can affect the way our feathered friends evolve, say scientists.

European birds called blackcaps follow a different “evolutionary path” if they spend the winter eating food put out for them in UK gardens.

The birds’ natural wintering ground is southern Spain, where they feed on the fruits that grow there.

Researchers describe the impact this well-intentioned activity has had on the birds in Current Biology journal.

Dr Martin Schaefer from the University of Freiburg in Germany led the research.

He and his team found that blackcaps that migrated to the UK for the winter were in the very earliest stages of forming a new species.

He explained that some blackcaps ( Sylvia atricapilla ) would always have migrated “a little further north” than others and eventually “ended up in Britain in the winter”.

“ It’s positive news for us, because it means not all the changes [humans] produce are necessarily bad ”
Martin Schaefer, University of Freiburg
“But those birds would have had nothing to eat,” he said.

It was when garden bird feeders became more popular in the UK, that an evolutionary division began to emerge.

“As soon as the British provided a lot of bird food, those birds would have had a much higher probability of surviving the winter.”

And because the UK is closer to their breeding ground, those birds would also have returned earlier to claim the best territory.

The researchers, from Germany and Canada, set out to discover if the birds that spent the winter availing themselves of garden bird-feeders were in fact a distinct group.

To do this, they studied the blackcaps at a breeding ground in Germany.

The team were able to use a chemical “signature” from the birds’ claws to identify where they spent the winter, and what food they ate.

“Then we took blood samples and analysed those to assess whether… we had two distinct populations. And that’s exactly what we found,” said Dr Schaefer.

“To a very large extent the birds only mate [with] birds with the same overwintering grounds as them.”

This initial “reproductive isolation”, Dr Schaefer explained, is the very first step in the evolution of a new species.

“This tells us that by feeding birds in winter we… produce an evolutionary split. And we have produced these initial steps in as little as 50 years.”

The team also observed differences in the birds’ beaks, wings and plumage.

Blackcaps that migrated along the shorter route to the UK had rounder wings, and longer, narrower beaks.

The scientists said these differences were evidence that the birds had adapted to their shorter journey, and to eating seeds and fat from bird-feeders, rather than fruit from shrubs and trees.

But, Dr Schaefer pointed out that the evolution of a new bird species “could take 100,000 to a million years”.

“At this stage this is reversible,” he added. “And it’s hard to envision a species change, because if there’s another economic crisis and people stop feeding the birds, the whole system might just collapse.”

Man-made change

In this case, Dr Schaefer thinks the human impact on blackcaps has been a positive thing.

“[The birds have] found a better overwintering area that is closer to the breeding ground, where they can obtain food easily.

“And I also think its positive news for us, because it means not all the changes we produce are necessarily bad, and that some species have the potential to adapt quickly to the changes.”

Grahame Madge from the Royal Society for the Protection of Birds (RSPB) said that this was “a fascinating piece of research” and that it fitted in with the birds adapting to a changing climate.

“Blackcaps have been able to start this behaviour because of the milder winter we’ve experienced in the last few decades,” he said.

“And because they’re getting food, this reinforces the behaviour and will enable them to survive a colder winter [in the UK].”

Joseph Tobias, a biologist from the Oxford University in the UK, agreed that the UK climate may have been a more important factor contributing to the changes observed in the blackcaps.

“The study clearly demonstrates that a new lineage has arisen… [but] it doesn’t actually demonstrate that food hand-outs by humans are the root cause,” Dr Tobias said.

“It is possible that the main reason for the switch in migratory behaviour was a warming winter climate in the UK. The best we can say on the basis of the evidence is that the increase in bird-feeding in the UK may have contributed to the switch in behaviour.”

Mr Madge added that putting food out for birds in the winter was “very important” and that many birds “need the energy boost at this time of year”.

Story from BBC NEWS:

http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/8393443.stm

Published: 2009/12/03 17:27:47 GMT

© BBC MMIX

Adapting to the freshwater crisis

Another good resource by Scientific American.

Good for discussion on sustainability next year.

Adapting to the fresh water crisis

Environmental Biology a hot subject

*Environmental biology a hot subject*
The Straits Times, 31 Oct 2009
By Grace Chua
*NUS, NTU to offer more courses in recognition of field’s growing value*

ENVIRONMENTAL biology is making a comeback here as well as worldwide, as
universities recognise the discipline’s role in the study of climate change and environmental issues like pollution.

Both the National University of Singapore (NUS) and Nanyang Technological University (NTU) plan to revamp their curricula to include more topics in the field, and the latter has applied for funding to set up a Research Centre of Excellence for environmental science.

As NUS’ biological sciences head Paul Matsudaira put it: ‘Singapore is at the epicentre of some of the major and most challenging environmental
problems that have to be addressed.

‘The equatorial location is one asset, since tropical environmental problems are comparatively under-researched.’

Like other biology disciplines such as molecular biology and genetics,
environmental biology is the study of living things, but in terms of their surroundings.

For example, it looks at how pollution and climate change affect species and biodiversity. Thus ecology, ecotoxicology and conservation biology might be considered aspects of environmental biology.

NUS, for instance, is offering several new courses on ecology and
evolutionary biology this year, and in the last two years, it has hired at least four new faculty members in biology.

Meanwhile, NTU’s school of biological sciences has hired several
international faculty members to study microbial ecology, said provost
Bertil Andersson.

NTU’s attention to environmental biology, the school’s expertise in earth sciences and its experience in environmental engineering are all part of a new university-wide Sustainable Earth initiative, which is expected to be launched formally in February next year.

But these changes are not driven solely by university administrations. They have also come about because of rising student interest.

One in five life sciences majors at NUS, for example, now opts for
environmental biology modules, up from 12 per cent seven years ago.

NUS started its integrated life sciences curriculum in 2001 and NTU started its School of Biological Sciences the following year, as part of a nationwide drive to train more students in the field.

But NUS biological sciences graduate Huang Danwei, now 28, felt he was not getting enough training in biodiversity and ecology. So in 2006, he and 10 others met the dean to propose curriculum changes.

The department listened to them, and classes in biodiversity and ecology are now available in the first- and second-year syllabuses.

There is demand for people with taxonomy skills and biodiversity know-how as fields like climate modelling and conservation grow.

For instance, the Agency for Science, Technology and Research’s Institute of High Performance Computing had a recent job posting for a research officer with ‘expertise in data management, database, climate change scenarios and biodiversity’.

But will these changes translate into real environmental policy changes or scientific advances?

Professor Matsudaira said he expects the biggest impact to come from the
development of science-backed environmental policy, where Singapore will
directly influence the Asia-Pacific region.

‘Because we are scientifically strong, we will train students and scientists for jobs in government, research and industry,’ he said.

However, students and universities should not jump on the bandwagon simply because the field is hot, warned National Institute of Education biologist Shawn Lum.

‘We should do it not because it’s a fad, but because as educational
institutions and as a country, we value it as a worthy field and endeavour, and our interest in it is not going to fall by the wayside the moment the next big thing comes along,’ he said.

caiwj@sph.com.sg

Copyright © 2007 Singapore Press Holdings. All rights reserved.

Creating a graph – online tutorial

Online tutorial for creating a graph by National Education Center for Education Statistics.

Island Biogeography and Evolution

ISLAND BIOGEOGRAPHY AND EVOLUTION: SOLVING A PHYLOGENETIC PUZZLE USING MOLECULAR GENETICS

R.P. Filson

Earth Pulse 2010 by National Geographic

A collection of beautiful graphics, updated figures and statistics in excellent diagrams.

Earth Pulse 2010 by National Geographic

Issues covered:
1. Population
2. Consumption of resource
3. Human Footprint