Y chromosome is smaller because it doesn't really contain as much genetic information as the X chromosome does.
X chromosome container several vital genetic information but Y has mostly genetic codes that are often redundant or obsolete and overridden by X except sexual development.
There are some animals like whiptail lizard which only have females because as they evolved their male allosome (the human equivalent of Y chromosome) became redundant and unnecessary.
idrather_be_dead t1_jbohyqu wrote
Reply to Why are Y chromosomes shorter than the X chromosome? by Which-Community-5851
Y chromosome is smaller because it doesn't really contain as much genetic information as the X chromosome does.
X chromosome container several vital genetic information but Y has mostly genetic codes that are often redundant or obsolete and overridden by X except sexual development.
There are some animals like whiptail lizard which only have females because as they evolved their male allosome (the human equivalent of Y chromosome) became redundant and unnecessary.