Friday, February 29, 2008
Thursday, February 28, 2008
One conclusion of this experiment is that it appears likely that lichens may be able to survive on the surface of Mars. Although the Martian atmosphere is very thin, it is filled with carbon dioxide, which is necessary for photosynthesis. However, long term survival and growth may be prevented by the low oxygen levels in the Martian atmosphere.
A paper in Genome Research by Matthew Webster of Trinity College Dublin, Ireland, and colleagues at Uppsala University in Sweden has proposed an explanation. They analysed the complete mitochondrial DNA genome in 14 dogs, six wolves, and three coyotes. This data suggests that mutations in the canine genome have played a bigger role in dog evolution than previously thought. Natural selection usually weeds out mutations in wild species if they offer no survival advantage. But if that pressure is removed, these mutations will get passed on. This provided dog breeders with a wide inventory of traits in the DNA to exploit. Others disagree, Webster et al. only studied mutations in mitochondrial DNA, which tends to accumulate more quickly than in nuclear DNA which forms the largest part of the genome. Far fewer mutations may have occurred in genes in the nucleus compared with mitochondria. Much of the variation we see in dogs may have to do with pre-existing variation from the ancestral wolf-dog population.
Wednesday, February 27, 2008
I learned lots of fascinating trivia from this article:
The project was actually an offshoot of a grant from the Department of Defense, which funded a project to study the possible biological effects of ELF (Extra Low Frequency) stations in the Upper Peninsula of Michigan. These ELF stations were built to communicate underground with ocean-going submarines in time of war.
They sampled for the fungus by 'baiting' with tongue depressors. The fungal mycelium quickly colonized the wood sticks.
They were not looking for a large fungus, or even trying to measure the size of any fungus. The project was originally to look at how mitochondrial DNA was inherited in fungi in nature.
When news of the 'giant fungus' broke in the press CNN wanted someone to go out into the woods and wave from the fungus so they could get an aerial picture of the humongous fungus.
Even better, a Japanese businessman called and wanted to build a boardwalk around the humongous fungus and charge people to view the 'pulsating mass of fungus'.
Tuesday, February 26, 2008
Monday, February 25, 2008
Having mentioned it in class I thought I'd see if I could find out whether Beatrix Potter was happy in her later life or whether she resented being excluded from the male dominated scientific community. Thanks to the wonders of the internet I found a highly relevant book and, even better, the relevant chapter is available online as a sample chapter.
Chapter 1 of Liaisons of Life, Beatrix versus the Botanists, by Tom Wakeford describes Beatrix Potter's encounters with the scientific establishment. Fascinating reading and a picture of science at the turn of the century. Beatrix Potter was facing an uphill battle, not just as a woman in science but also in proposing lichens as a symbiotic and mutualistic association. James Crombie, a prominent English naturalist said:
"A useful and invigorating parasitism who ever before heard of such a thing?"
and he described the relationship as:
"an unnatural union between a captive algal damsel and a tyrant fungal master."
After her aborted scientific career and her successful career as a children's author Beatrix Potter went on to a third, and equally successful career as a sheep breeder and conservationist in the English Lake District.
Sunday, February 24, 2008
Saturday, February 23, 2008
Specially trained dogs sniff and dig them out, and are rewarded with doggy treats. Pigs — bigger, hungrier and harder to manage — have largely fallen out of favor.
Friday, February 22, 2008
Thursday, February 21, 2008
Work carried out at UC Berkeley and published in PNAS last year now suggests that the fungus may end up playing a bigger role in the frog's demise than previously thought because of the pathogen's ability to spread over long distances and possibly persist in the environment as a consequence of sexual reproduction. A study of the genetics of the fungus provided the first evidence of genetic recombination in B. dendrobatidis, which results in multiple, related genotypes and suggests that sexual reproduction is occurring - even though spores have not been discovered.
This work was carried out in the Briggs lab in Integrative Biology in association with the Taylor lab in Plant and Microbial Biology and is part of a larger project on chytridiomycosis (the disease caused by B. dendrobatidis) and the mountain yellow-legged frog led by Cheryl Briggs, UC Berkeley associate professor of integrative biology. Cherie has now moved to UCSB so there is an opportunity to get involved in this research if it interests you.
Wednesday, February 20, 2008
Using functional and symbolic design features for Polynesian canoes, we show that natural selection apparently slows the evolution of functional structures, whereas symbolic designs differentiate more rapidly. This finding indicates that cultural change, like genetic evolution, can follow theoretically derived patterns.
Nina Jablonski, chair of the Anthropology Department at Pennsylvania State University, said "This paper is revolutionary in its approach … one of the most significant papers to be written in anthropology in the last 20 years."
Tuesday, February 19, 2008
A favorite Botany site is the Botany photo of the day from the University of British Columbia Botanical Garden. They always seem to have some new interesting plant fact with some great photographs
Plants may not have the cute behavior of animals but they are sure good at staying still while people photograph them. Well, except when it's windy....
There are lots of interesting photographs and stories at this site. If you are familiar with the cork oak outside UCSB library (at the corner of the library nearest the bike path) you might be interested to see how a harvested cork oak looks. They only harvest the cork every decade but the harvest from a single tree can be up to a tonne!
Note the taxonomic index on the right hand side of the page which allows you to jump straight to pictures of mosses, ferns, liverworts, plants and insects etc etc.
Monday, February 18, 2008
A team from UCL and Stony Brook University, New York, have discovered a fossil of a giant dinosaur-eating frog in Madagascar, giving weight to the theory that the island off Africa’s east coast was once linked to India and South America.
You can read a fairly good report on the BBC website but there were numerous other press reports today. Everybody seems to love the picture.
Oh man, what's not to love about this story? It's a giant frog, it's got one of the best scientific names I think I've ever come across and there's a beautiful artists reconstruction. Does it remind anyone else of hypno-toad?
Sunday, February 17, 2008
Wolbachia is a is a genus of inherited bacterium that infects a high proportion of all insects. They are the world's most common parasitic microbes and often lead to the death of males.
Over only 10 generations that spanned less than a year, the proportion of males of the Hypolimnas bolina butterfly on the South Pacific island of Savaii jumped from 1 percent of the population to about 39 percent. The researchers considered this a stunning comeback and credited it to the rise of a suppressor gene that holds in check the Wolbachia bacteria, which is passed down from the mother and selectively kills males before they have a chance to hatch.
"To my knowledge, this is the fastest evolutionary change that has ever been observed. This study shows that when a population experiences very intense selective pressures, such as an extremely skewed sex ratio, evolution can happen very fast."
The fieldwork for this study was carried out on two South Pacific Islands and the researchers were based out of UC Berkeley's Richard B. Gump South Pacific Research Station on the island of Moorea in French Polynesia. I mention this because although the field station is run by Berkeley, UC Santa Barbara runs the Moorea Coral Reef Long Term Ecological Research Program and there are plenty of opportunities to get involved in this research if that is where your interests take you.
Friday, February 15, 2008
The farmed fish spread diseases and parasites to wild salmon. Some cultivated escapees also interbreed with the native fish, reducing the ability of their offspring to survive, researchers say.
Outbreeding depression and gene flow in action. From a paper in PLOS this week (paper and summary) as reported on by National Geographic. If you go to the National Geographic website you should check out the blood squirting lizard....
Thursday, February 14, 2008
Berkeley, for example, has a tremendous set of museums and has much of their data online and searchable already.
In another lifetime I worked on some websites at Berkeley and one of them had a table of all the departments, research groups and museums studying ecology and environmental change in California. This may be useful link to bookmark if you ever need museum data. Although I notice it's already out of date since I think I did most of the work in 2004 or 2005 and since then CCBER has replaced the Museum of Systematics and Ecology at UCSB. There are also pages of links to field sites, field stations, state agencies and much more.
For those who enjoy very slight coincidences (everyone, right?). I just finished reading 'Anthrax: The Investigation of a Deadly Outbreak' about the Sverdlovsk anthrax leak, an incident where spores of anthrax were accidentally released from a military facility in the city of Sverdlovsk in the former Soviet Union in 1979. The ensuing outbreak of the disease resulted in 94 people becoming infected, 64 of whom died over a period of six weeks. The outbreak was denied by the Soviet Union for decades. Prior to communist rule Sverdlovsk was known as Yekaterinburg. In fact it has reverted to this name again today. Having gone my whole life without ever hearing of this town it seemed a coincidence to hear that was where Katherine Essau was from.
Wednesday, February 13, 2008
UPDATE: a number of CCS students have already risen to the task. There is now a thread for CCS itself which would be an appropriate place to add comments if you have anything to add.
Tuesday, February 12, 2008
There are a number of useful resources on the web to help you understand the relationship between the different plant groups and explore their diversity.
The Tree of Life is a collaborative project that provides information about the diversity of organisms on Earth, their evolutionary history and their characteristics. The link above takes you to the main page or you can skip directly to the green plants.
The Green Plant Phylogeny Research Group (Deep Green) is a group that coordinates research into the phylogeny of the green plants. Their website contains a useful hyperbolic tree. Hyperbolic trees are one way to display complex trees clearly. I posted a link to the hyperbolic trees earlier when we talked about phylogenies.
The Green Tree of Life aims to resolve the primary pattern of evolutionary diversification among green plants. An overview of the results to date can be seen in this poster.
Monday, February 11, 2008
This story includes plants, insects, climate change, fossils and herbivory. Accordng to a study of 5000 fossil leaves a period of increasing temperature 55 million years ago led to a huge increase in the percent of plants that were being attacked. This is thought to be because insects do better and plants are more nutritious as it gets warmer. This study could obviously have implications for the global change we are currently seeing.
This is a great website with information about algae. I found it while trying to figure out where in the heck a thin leafy green algae like "sea lettuce" (Ulva/Enteromorpha) hid its reproductive structures or cells, especially since both gametophyte and sporophyte life stages look so similar. Check it out. There are even recipes!
You can choose to "enter Enteromorpha" if you dare, by clicking here:
Sunday, February 10, 2008
I mentioned this briefly in class for some reason. It might be more MCDB1A material but it's amazing stuff. Here's the news article from Science where they published the study and an article from Wired magazine that reveals what Venter's 'watermarks' are.
With the help of what he calls "digital biology," he can begin to redesign life.
Saturday, February 9, 2008
Friday, February 8, 2008
It turns out the answer is quite simple but that I'd been thinking too specifically. We just need to think outside the box for a moment and consider using phylogenies for groups other than the one we might be specifically studying.
A vicariance event will affect many different taxa and leave similarities in their cladograms. For example the breakup of Gondwana caused deep divisions in the cladograms of many groups representing the now separated continents. These similar cladograms are 'congruent'. Lack of congruence in cladograms is better explained by dispersal. Obviously this only works on a larger scale. I thought this page explained it all quite clearly.
Thursday, February 7, 2008
From what they are now calling a 'cult' movie, Idiocracy. Based on the politically incorrect question of what would happen if unintelligent people outbreed intelligent people, creating a future society which is a few sandwiches short of a full picnic. Which I guess makes it slightly relevant to our class. Plus, you now know what plants crave.
Wednesday, February 6, 2008
Tuesday, February 5, 2008
For some years the mouse, found in Colorado and Wyoming, has been on the federal endangered species list. Its declining numbers are probably due to habitat loss and much of the remaining mouse habitat is also under threat. Its preferred habitat is a narrow band of land along the eastern edge of the Rocky Mountains that is being keenly eyed by developers.
A subspecies, by definition, differs morphologically from members of other subspecies of the species. Subspecies may, in some cases, be on their way to forming full species. In other cases they may not ever form separate species but will contain important genetic variation. Although the endangered species act preserves both species and 'subspecies' there is no clear definition of how distinct a 'subspecies' has to be before it deserves separate protection. In the current case opinions are sharply divided over whether the Preble's Jumping Mouse is distinct enough from the more common Bear Lodge meadow mouse. The story was summarized by the Jackson Hole Star Tribune when the US Fish and Wildlife Service convened a panel of scientists to review the evidence. A google search on the mouse will show the history of the debate.
This may sound like a small academic debate but it could have important outcomes for how the endangered species act is interpreted in the future. Genetic data is becoming increasingly important in deciding what is a valid subspecies but there are no guidelines for how much genetic difference is required between two populations for them to be considered different subspecies.
There are a lot of issues here, some of which we touched on and some of which we will touch on in the ecology section. It is important to realize that we may not currently have enough information to make these decisions.
Zebra (stallion) + horse (mare): zorse, zebra mule, zebrule or golden zebra
Zebra (stallion) + pony (mare): zony
Zebra (stallion) + Shetland pony (mare): zetland
Zebra (stallion) + any ass species (jenny): zebrass
Zebra (stallion) + donkey (jenny): zedonk, zeedonk, zonkey, zebronkey, zebadonk
Zebra (mare) + donkey (sire): zebrinny
Zebra (mare) + horse (stallion): hebra
Apparently they were mentioned by Darwin: in the Origin of Speies he refers to four coloured drawings of hybrids between the ass and zebra. These crosses are usually sterile. The Zorse article has some comments on genetics:
Zebras, donkeys, and horses are all members of the family equus -- equines. Equines can be crossbred to produce hybrids. They are all slightly different in genetic makeup, but still all equines. That is, horses have 64 chromosomes, zebra have between 44 and 62 (depending on species). Zorses can be male or female, but are sterile since their chromosome count is 63.
Just in case you think I get all my information from Wikipedia I'll also refer you to the wonderfully named International Zebra-Zorse-Zonkey Assocation. Lots of information and pictures and even a Zonkey for sale. Where else but at the Spots 'n Stripes Ranch in California. I didn't know I wanted a Zonkey, but now I do.