7E Science ASB

The classical twin study design relies on studying twins raised in the same family environments. Monozygotic (identical) twins share all of their genes, while dizygotic (fraternal) twins share only about 50 percent of them. So, if a researcher compares the similarity between sets of identical twins to the similarity between sets of fraternal twins for a particular trait, then any excess likeness between the identical twins should be due to genes rather than environment.Researchers use this method, and variations on it, to estimate the heritability of traits: The percentage of variance in a population due to genes. Modern twin studies also try to quantify the effect of a person's shared environment (family) and unique environment (the individual events that shape a life) on a trait.The assumptions those studies rest on--questioned by some psychologists, including, in recent work, Jaccard--include:

Cloned animals are normally considered to be more alike than those that are conceived naturally

the Basic Steps of Cloning

Isolation of the Donor Nucleus

Harvest of Egg Cells

Professor Julian Savulescu said that creating so-called designer babies could be considered a "moral obligation" as it makes them grow up into "ethically better children". The expert in practical ethics said that we should actively give parents the choice to screen out personality flaws in their children as it meant they were then less likely to "harm themselves and others". The academic, who is also editor-in-chief of the Journal of Medical Ethics, made his comments in an article in the latest edition of Reader's Digest. He explained that we are now in the middle of a genetic revolution and that although screening, for all but a few conditions, remained illegal it should be welcomed.

Cross-border co-operation on terrorism and crime will be compromised unless the UK updates the technology it uses for DNA profiling, experts have warned.

Using EU recommended markers Not using recommended markers Dat

Experts also say that the "chemistry" that underlies DNA testing kits used by UK forensic science labs is now more than a decade old and that newer, more sensitive systems can obtain results from even low quality samples - improving success rates. Some argue that such information can potentially make or break a case.