If you take a look around you, chances are pretty good that within a few seconds, your eyes will fall on some kind of ...

Biological sex is usually described in simple binary terms: male or female. This works well for germ cells (sperm versus eggs), but for other body organs it is of little help. A new study by the Max ...

Bill introduced by Senate Republicans would designate people as either “male” or “female.” Authors say the legislation protects women, and critics say it leaves out portions of the population. The ...

Please provide your email address to receive an email when new articles are posted on . Differences between female eyes and male eyes have not yet been fully considered. Eye care needs to account for ...

CNN hosts derided Health and Human Services (HHS) Secretary Robert F. Kennedy Jr.’s new guidance on biological differences between men and women, claiming such "new definitions" are more restrictive ...

It’s not just about chromosomes. Or reproductive cells. Or any other binary metric. Many genetic, environmental and developmental variations can produce what are thought of as masculine and feminine ...

Male and female king cobras, despite their similarities, have distinct differences in size, color, behavior, and reproductive roles. Males grow larger, are more vibrant, and engage in territorial ...