Many scientists spend their lives trying to answer just one question. But geneticist Jack Szostak says there’s lots of problems to solve. He spent the first two decades of his career investigating chromosomes, specifically the role played by telomeres, tiny structures at the ends of chromosomes, and the enzyme telomerase, which revolutionized what we know about the aging process.
That research, from the 1980s, earned him a share of the 2009 Nobel prize for physiology or medicine. In the 1990s, Szostak turned his attention to RNA and its role in the early evolution of life.
Tag: evolution
A Nobel Winner Looks to Create Life in His Lab
Many scientists spend their lives trying to answer just one question. But geneticist Jack Szostak says there’s lots of problems to solve. He spent the first two decades of his career investigating chromosomes, specifically the role played by telomeres, tiny structures at the ends of chromosomes, and the enzyme telomerase, which revolutionized what we know about the aging process.
That research, from the 1980s, earned him a share of the 2009 Nobel prize for physiology or medicine. In the 1990s, Szostak turned his attention to RNA and its role in the early evolution of life.
Pornography, Sperm Competition, and Behavioural Ecology
Over millions of years, evolution by natural selection has produced adaptations in humans: biological and psychological traits that improved human survival and reproduction in ancestral environments. For example, ripe fruit was an infrequent but calorically rich part of the human ancestral diet. We therefore have a sweet tooth that rewards us when we eat ripe fruit.
Research Focuses on Evolution of Sex and Gamete Function
The propagation of every animal on the planet is the result of sexual activity between males and females of a given species. But how did things get this way? Why two sexes instead of one? Why are sperm necessary for reproduction and how did they evolve?
These as-yet-unresolved issues fascinate Timothy Karr, a developmental geneticist and evolutionary biologist at Arizona State University’s Biodesign Institute. To probe them, he uses a common fruit fly, Drosophila melanogaster-an organism that has provided science with an enormous treasure-trove of genetic information.
“My research focuses on the evolution of sex and in gamete function,” Karr says. “I focus primarily on the sperm side of the sexual equation. I’m interested in how they originated and how they are maintained in populations.”
Karr’s current study, in collaboration with researchers at the University of Chicago, recently appeared in the journal BMC Biology. The study reexamines an earlier paper that analyzed the sex chromosomes of fruit flies during spermatogenesis-the process that produces mature sperm from germ cells.
While the previous paper, by Lyudmila M Mikhaylova and Dmitry I Nurminsky, argued against the silencing of sex-linked genes on the X chromosome in Drosophila during meiosis-a process referred to as Meiotic Sex Chromosome Inactivation (MSCI) -the reanalysis presented by Karr suggests MSCI is indeed occurring.
The work sheds new light on the evolution of sperm structure and function, through an analysis of Drosophila genes and gene products. As Karr explains, the research has important implications for humans as well: “The more direct, biomedical aspect is that when we learn about the function of a gene that encodes a protein in Drosophilasperm, we can immediately see if there’s a relationship between these genes and their functions and known problems with fertility in humans.” Read full article.
Evolutionary Theory and the Older Dad
by Corey Whelan
According to Wikipedia, evolution is defined as a “slow change in groups of living things over time”. One of the tenets of evolutionary theory is that people should actually die of old age once their reproductive lives are …