ፍትህ ለሁሉም / Justice for All
Natural selection is a mechanism of evolution. Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success. This process causes species to change and diverge over time. Natural selection is one of the ways to account for the millions of species that have …
The Theory of Evolution by natural selection was first formulated in Charles Darwin’s book “On the Origin of Species” published in 1859. In his book, Darwin describes how organisms evolve over generations through the inheritance of physical or behavioral traits, as National Geographic explains. The theory starts with the premise that within a population, there is variation …
Researchers found that culture helps humans adapt to their environment and overcome challenges better and faster than genetics. Tim Waring and Zach Wood found that humans are experiencing a ‘special evolutionary transition’ in which the importance of culture is surpassing the value of genes as the primary driver of human evolution. Due to the group-orientated …
The process of human adaptation to novel environments is a uniquely complex interplay between cultural and genetic changes. However, mechanistically, we understand little about these processes. To begin to untangle these threads of human adaptation we use mathematical models to describe and investigate cultural selective sweeps. We show that cultural sweeps differ in important ways …
Human cultural traits—behaviors, ideas, and technologies that can be learned from other individuals—can exhibit complex patterns of transmission and evolution, and researchers have developed theoretical models, both verbal and mathematical, to facilitate our understanding of these patterns. Many of the first quantitative models of cultural evolution were modified from existing concepts in theoretical population genetics …
Selection of parents for the generation of heterosis Heterosis refers to the superior phenotypes observed in hybrids relative to their inbred parents with respect to traits such as growth rate, reproductive success, and yield. Heterosis was discovered in maize about a century ago and has subsequently been found to occur in many crop species. The increase …
Inbreeding, or mating between two closely-related people, is a strong taboo across the world. There’s a good reason for this, of course. The potential for sexual abuse and lasting trauma is high, and the odds of inheriting rare genetic diseases go up exponentially among children who are the result of inbreeding. Read more
The study, reported in the journal Science, examined genetic information from the remains of anatomically modern humans who lived during the Upper Palaeolithic, a period when modern humans from Africa first colonised western Eurasia. The results suggest that people deliberately sought partners beyond their immediate family, and that they were probably connected to a wider network of …
Genes come in different varieties, called alleles. Somatic cells contain two alleles for every gene, with one allele provided by each parent of an organism. Often, it is impossible to determine which two alleles of a gene are present within an organism’s chromosomes based solely on the outward appearance of that organism. However, an allele that is hidden, …
Scientists first discovered chromosomes in the nineteenth century, when they were gazing at cells through light microscopes. But how did they figure out what chromosomes do? And how did they link chromosomes — and the specific genes within them — to the concept of inheritance? After a long period of observational studies through microscopes, several …