Why are males and females 50%-50%?

[TexasProgresive]

26. This from an earlier post of mine

The chart in the link does not reflect birth or conception ratios but starts with an equal number 100,000. The males start declining immediately which increases at adolescence.

At birth there is a higher percentage of males to females. This starts shifting right from the beginning. The link is to an actuarial life table that shows the chance of dying in each year of birth. for males it begins higher and becomes radically higher in the teens. That would be from risky behavior but the death rates for males remain higher until the unrealistic age of 116.

There could be any number of factors as to why. Here some possibilities:
1) There is an inherent weakness in the male that leads to early death.
2) It takes fewer males to propagate the species.
3) Males more likely to engage in risky behavior.
3) Longer living females ensure offspring growing to adulthood.

http://www.ssa.gov/oact/STATS/table4c6.html