Showing posts from 2014

Evolution, in real-time

Plant-insect interactions constitute fundamental component communities of terrestrial ecosystems [1] [2] . The different types of plant-insect associations in nature are thought to have driven both plant and insect radiation [3] . The advantages of animal-mediated pollination have led to the evolution and diversification of specialist mutualisms between, for instance, plants and birds (e.g. [4] ), while the need for protection has spawned mutualisms between various tropical tree species and ants [5] [6] [7] . Herbivory, on the other hand, has led to an arm’s race of plant defence mechanisms and insect attack and feeding habits [3] . An ever-increasing number of studies demonstrate the importance of biotic interactions in driving evolutionary change, but considerably fewer reveal the mechanisms by which this occurs in real-time [8] [9] . Monarch caterpillar ( Danaus plexippus ) on milkweed ( Asclepias syriaca ). Credit: Kailen Mooney

Pollinators get a buzz off caffeine, too

Most plants can reproduce asexually – that is, new plant life is created without the need for female and male sex cells to combine. However, amongst plants there is a variety of ways in which they can reproduce sexually. Sexual reproduction confers certain advantages to organisms: for example, by the remixing of sexual cells, more variation is maintained within a population and there are more likely to be some organisms able to withstand environmental changes. Animal-mediated pollination is a common way by which plants distribute their sex cells to other individuals in a population. Plant have evolved a wide variety of mechanisms to increase the likelihood of pollination, including conspicuous flowers, enticing scents, and sweet nectar rewards. Coffea and Citrus are plant genera which both exhibit attractive flowers and produce more fruit and seeds when pollinated by bees (Ricketts, 2004), which they reward with nectar. However, the nectar of species in these genera contain another,

Happy World Turtle Day! 2014

To celebrate World Turtle Day (and here I'm using the word turtle broadly to mean all Testudines/Chelonia), here are some photos of sea turtles I took while snorkelling around León Dormido and Giant Galápagos tortoises on Santa Cruz, both in the Galápagos Islands. Plus a drawing that I don't appear to ever have finished... Drawing turtle wrinkles is really boring. © X O'Reilly

Why is the world's richest biodiversity hotspot so biodiverse? Part 1

Today, 22nd of May, is the International Day for Biodiversity. This time last year, I was living in one of the most biologically rich places of the planet, somewhere on the eastern edge of Ecuador's share of the Tropical Andes biodiversity hotspot ( figure 1 ). As the name suggests, this hotspot englobes the tropical portion of the Andes mountain range, along with its immediate foothills as they spill out into the Amazon rainforest. Figure 1 - Tropical Andes hotspot shaded in dark grey. © X O'Reilly According to some criteria, the Tropical Andes hotspot ranks as the most biodiverse of the biodiversity hotspots. As far as science has thus far revealed, this area holds around 45,000 plant species, nearly half of which are endemic – that is, not native anywhere else. This is both the greatest number of absolute plant species and endemic plant species found in any one biodiversity hotspot. The Tropical Andes also boast more species of terrestrial vertebrate animals than an

Warm pockets during cold times and a rediscovered species

For the last 6 million years or so, the Earth has been subjected to drastic temperature fluctuations. During the Pliocene, the Earth underwent cycles of warm wet and cooler dry periods. Substantial continental ice began to form in the Northern Hemisphere around 3 million years ago (Mya), before the planet was plunged into a series of ice ages. Although you may think of an "ice age" as a snowy period after which woolly mammoths and neanderthals disappeared, you may not know that currently we are simply enjoying a "summer" break from this ice age. The last 2 millions years of Earth's history has consisted of various glacial periods interspersed by warmer times, known as interglacial periods.

A gene that protects malarial parasites from mosquito defences

Despite a relatively low mortality rate, there are hundreds of millions of malaria cases worldwide per year, making the parasitic disease responsible for a massive annual death toll [1,2] . The definitive hosts of the apicomplexan parasites that cause malaria ( Plasmodium spp ) are anopheline mosquitoes, and various attempts have been made in endemic areas to control mosquito populations as a means of limiting or interrupting transmission [3] . Malaria’s pantropical distribution – therefore, prevalence mostly in developing countries – means that even controlling vector transmission is met by a suite of social, economical, and political obstacles. The same combination of issues added to the parasite’s complex life cycle, have hinder widespread treatment or the development of effective vaccines.