12th edition of my human genetics textbook


Glenn Nichols, surrounded by his hospice team. The author is in yellow.

Genetic Linkage

How the Vampire Bat Came to Feed on Blood, and What We Can Learn From Its Droppings

March 2, 2018

Tags: forensic entomology

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. (more…)

Tracking RNA to Pinpoint Time of Death: Better Than Bugs?

February 28, 2018

Tags: forensic entomology

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 (more…)

Project to engage students in helping families with rare genetic diseases
Book Club Reader's Guide
Many challenging questions to stimulate thought and discussion.
Instructor's Guide
38 discussion questions to get students thinking and talking about gene therapy, including the science, ethical issues, and the drug approval process.
Narrative science
The Forever Fix is the uplifting true story of 8-year-old Corey Haas, who was cured of hereditary blindness just 4 days after gene therapy.
College Textbooks
A spectacularly-illustrated, clearly written human anatomy and physiology textbook, used in pre-health profession programs throughout the U.S.
A highly engaging, clearly written, beautifully illustrated introduction to the science of human genetics for the non-scientist. Now in its 11th edition, 12th to be published in September 2018.
An ideal starting point for anyone who wants to know more about genes, DNA, genomes, and the genetic ties that bind us all.

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