Ricki Lewis

Why do the three species of vampire bats eat only blood, compared to the 1,240 other species that are perfectly happy to eat such things as figs, mangoes, dates, bananas, birds, fish, frogs, lizards, and even other bats? Many thrive on beetles, moths, and mosquitoes. A single brown bat zooming across a backyard on a summer’s eve can eat 500 mosquitoes in an hour.

Types of Vampire Bats

The three species of vampire bats descended with other bats from a shared ancestor some 26 million years ago. Four million years later – fast in evolutionary time – the three species had refined the ability to survive by drinking blood.

Vampire bats are so stealthy, and their cuts so tiny, that it isn’t uncommon for prey to sleep through the feeding. They live from southern Argentina to northern Mexico, but may venture near Texas and Florida as the climate changes. Fossils indicate they lived in the US 5000 to 30,000 years ago. Read More 

DNA is a persistent molecule. Genome sequencing is possible for creatures as ancient as mummies and mammoths. But the messenger RNA (mRNA) molecules that translate a gene’s information into a specific protein are more ephemeral, waxing and waning in a tissue over time, even after death, due to the instability of the sugar part of the molecule.

A multinational team has adapted the changeability of gene expression – mRNA production – into a computational tool that uses transcriptomes – the sets of mRNAs in particular body parts – to deduce time since death. In forensics terms, that’s the postmortem interval (PMI). Roderic Guigó led the team that includes researchers from Portugal, Spain, and the Broad Institute at Harvard. Their report appears in Nature Communications.

The Worms Crawl In, The Worms Crawl Out Read More