But there’s a downside to making a big, showy display to attract pollinators—you might also attract visitors who have less helpful intentions than gathering up some pollen and moving on to the next flower. Showy flowers might attract animals that steal the rewards offered to pollinators—or they might attract animals that eat the flowers themselves, or the developing seeds created by pollination. So the evolution of attractive floral displays might very well be a compromise between attracting the right visitors, and attracting the wrong ones.
Whether the weather be cold, or whether the weather be hot
we’ll be adapted whatever the weather, whether you like it or not.
Life is risky for a newly hatched lizard. You have to make your way in a habitat you’ve never seen before, full of all sorts of larger animals that think you’d make a decent snack, if maybe not a full meal. Wouldn’t it be nice if you could’ve been preparing for the conditions you’ll meet out there even before you crack through that shell?
Well, for one species of skinks, it looks like this may be exactly what happens. A recent paper in The American Naturalist makes the case that rainbow skinks (Carlia longipes) develop in their eggs to match the habitat conditions around their nest—based on the temperature of the nest.
This post is a guest contribution by Michael Harvey, graduate student in Robb Brumfield‘s lab at the Museum of Natural Science at Louisiana State University. Mike studies avian evolution, phylogenomics, and Neotropical ornithology.
Blackwater river…approximate Bayesian computation…dawn song…genomic islands…wing chord…target DNA enrichment…
My life as an evolutionary biologist straddles two worlds. I study the comparative phylogeography of Amazonian birds, and on the one hand my research involves laboratory and computational methods that push the limits of new technologies and analytical techniques, and on the other, expeditions to the tropics that are nearly indistinguishable from the natural history work conducted by Victorian era biologists. I am a PhD student at Louisiana State University, and for most of the year my work is in the lab and at my desk. For several months of the year, however, my work is general ornithological collecting expeditions to the Amazon Basin.
Every Friday at Nothing in Biology Makes Sense! our contributors pass around links to new scientific results, or science-y news, or videos of adorable wildlife, that they’re most likely to bring up while waiting in line for a latte.
First of all, my deepest apologies for the lateness of this post. As you may know I am a 4th year medical student and today was Match Day and I was deep in the throws of celebrating the completion of 4 years of medical education as well as learning where I will be training for the next three years in Family Medicine. So, without further adieu, your links for this week.
CJ decided to that there were too many good links and had to share several. First, as a skater herself she found an article relating to transmission of skin flora between close team mates and those competing in roller derby. Next she decided to share how the sequester is going to affect science jobs and the next few years could be difficult. But finally, a cool post on five animals that could possibly take over the world, which makes me look at spiders a little closer now.
Next, Jeremy likes the fact that new evidence from the Mars rover is favorable to the possibility of conditions that could have sustained life on the red planet.
From Noah, a video documenting several scientists as they inventory one of the worlds most biodiverse locations, the Yasuni Biosphere Reserve.
Finally, in the spirit of March Madness, from Devin comes a battle of the Mammals. “Mammal March Madness from the Mammal’s Suck blog. Although the tournament is purely fictional, the facts and natural history information given out during the extended live tweet rounds are amazing. The first rounds are already complete, but tune in for the exciting finals. Live action via twitter: @Mammals_Suck and general info via the website:”
Cross-posted from Denim and Tweed.
Remember the Molecular Ecologist symposium I attended as part of the 2012 Evolution meetings in Ottawa? Well, there’s going to be a sequel, launching Wednesday in convenient online format.
The Molecular Ecologist will be hosting speakers from the Ottawa symposium in a live-chat on the blog, starting at 9 a.m. US Central Time and running until noon (that’s 3-6 p.m. GMT, for those of us located outside North American). We’re trying out a live-chat service called CoverItLive, which will let readers follow the coversation and submit questions and/or comments directly from the blog — test runs have gone pretty smoothly, and I’m excited to see how this works as a medium for scientific discussion.
If you want to review the Ottawa symposium beforehand, check out the archived material at the Molecular Ecology websited. To indicate your interest and submit questions in advance, e-mail Molecular Ecology Managing Editor Tim Vines; otherwise, just join us Wednesday morning at The Molecular Ecologist.◼
Evolutionary biologists are fascinated by islands. There are a number of reasons for this. Islands systems can act as natural evolutionary experiments. They are small, less biodiverse, and isolated, so their biota can often be treated as simplified models of more complex mainland ecosystems (e.g. Darwin’s finches on the island Daphne Major). Ecologically similar islands can also act as replicates, with related taxa playing out the same evolutionary scenarios over and over again in isolation (e.g. Caribbean Anolis). Or they can act as life preservers, providing isolated strongholds for ancient evolutionary lineages that have long been extinct in the rest of the world (e.g. the Tuatara of New Zealand).
The Socotra archipelago is a particularly interesting, but poorly studied island system. Socotra consists of four islands in the Indian Ocean. It is extremely isolated (150 miles from the horn of Africa, 240 miles from the Arabian Peninsula) yet it has a continental origin. That means it was once part of the supercontinent Gondwana and suggests that some species may have lived there since it first became an island (~17.6 million years ago). Socotra has a very high level of endemism, with 37% of its plant species and 90% of its reptiles occurring nowhere else. As the islands are very remote and in a politically unstable part of the world, most of this unique biodiversity has not been studied using modern techniques. The islands are rugged and mountainous, reaching 1500m elevation, and primarily classified as tropical desert, making for a fairly fantastical landscape. A recent paper by Goméz-Diaz et al. (2012) takes a broad-brush approach to characterizing a chunk of Socotra’s obscure diversity: the Hemidactylus geckos.
This post is a guest contribution by Kathryn Turner, a PhD student at the University of British Columbia, who studies the evolution of invasive thistles. Kathryn writes about her scientific interests at the slyly named site Alien Plantation and tweets under the handle @KTInvasion.
Invasive species are a big problem. A real big problem. In the US alone, invasive species cost nearly $120 billion in damages per year (Pimentel 2005). 42% of species on the Threatened and Endangered list are there primarily because of invasive species.
Which leaves us with two questions. First, most obviously, how is it that a species is able to come into a new environment that it is not adapted to, surrounded by new environmental conditions and foreign biological interactions, and thrive? Thrive so exaggeratedly, that it can out-compete and displace species which have been there for millennia, adapting precisely to those environmental conditions and biological interactions? How can an individual survive to propagate a population? How can any species accomplish this? Second, less obviously: why can’t more species do it? Humans transport animals and seeds (and spores and larvae, etc, etc) around all the time, but only 10% establish self-sustaining populations, and only 1% spread to new habitats, becoming potentially invasive; this is known as the ‘tens rule’ (Williamson 1993) – a funny ‘rule of thumb’ for which I could never quite figure out the math.
Actually, that’s not really true. Biologists generally agree that predators, prey, parasites, and competitors can exert natural selection on the other species they encounter, but we’re still not sure how much those interactions matter over millions of years of evolutionary history.
On the one hand, groups of species that are engaged in tight coevolutionary relationships are also very diverse, which could mean that coevolution causes diversity. But it could be that the other way around: diversity could create coevolutionary specificity, if larger groups of closely-related species are forced into narower interactions to avoid competing with each other.
Part of the problem is that it’s hard to study a species evolving over time without interacting with any other species—how can we identify the effect of coevolution if we can’t see what happens in its absence? If only we could force some critters to evolve with and without other critters, and compare the results after many generations …
Oh, wait. That is totally possible. And the results have just been published.
This post is a guest contribution by Colin Beale, a research fellow at the University of York who studies ecology in Tanzania. Colin writes about the living community of the savannah, from butterflies to wildebeests, with co-blogger Ethan Kinsey at Safari Ecology. If you have an idea for a post, and you’d like to contribute to Nothing in Biology Makes Sense, e-mail Jeremy to inquire.
Spinescent. Now there’s a word! It simply means having spines and one of the first things many visitors to the African savannah notice is that everything is covered in thorns. Or, in other words, Africa is spinescent. It’s not a wise idea to brush past a bush when you’re walking, and you certainly want to keep arms and legs inside a car through narrow tracks. These are thorns that puncture heavy-duty car tyres, let alone delicate skin. But why is the savanna so much thornier than many of the places visitors come from? Or even than other biomes within Africa, such as the forests?
At one level the answer is obvious—there are an awful lot of animals that like to eat bushes and trees in the savanna. Any tree that wants to avoid this would probably be well advised to grow thorns or have some other type of defence mechanism to protect itself. But then again, perhaps the answer isn’t so obvious: all those animals that like to eat bushes seem to be eating the bushes perfectly happily despite the thorns. So why bother having thorns in the first place? There’s certainly a serious cost to having thorns: plants that don’t need to grow them have been shown in experiments to produce more fruits. So if animals eat the plants with thorns anyway, why pay this cost?
As humanity spreads out over the globe, finding ever more clever ways to domesticate wild landscapes and harness natural processes to its will, many species of wildlife find their natural distributions becoming fragmented. Iconic North American species such as grizzly bears, red-cockaded woodpeckers, and the American burying beetle today inhabit only small fractions of the ranges they occupied only 100 years ago. A result of this fragmentation is that many individuals exist in small, isolated populations. In these populations, a curious phenomenon often emerges, one that can only be understood in light of some basic evolutionary theory. That phenomenon is known as inbreeding depression, and it refers to the decline in average fitness of individuals in a shrinking population.
Inbreeding depression is essentially a result of individuals in small, isolated populations being more likely to mate with close relatives. It’s well known that mating with close relatives produces less fit offspring, and the aggregate effect in natural populations is seen as low average fitness and an ensuing low population growth rate. This can be a serious problem in populations subject to conservation efforts because even after protective measures have been taken (removing threats, restoring habitat) recovery can be hindered by inbreeding depression. Inbreeding depression is slightly more complicated than this, however, because it is not consistently seen in all small populations. In some island populations with very small population sizes (such as the Chatham Robin, Petroica traversi) inbreeding depression has not been observed (Jamieson et al. 2006).