Genesis 1:24-31

On the 6th day, God creates land animals. Then, God creates His crowning achievement. The thing that He has been making preparations for - man. Notice that God had made EVERYTHING for man's enjoyment, from plant life to animal life, before He created man. Everything that man needed to be prosperous and happy was ready when man was made. Also, notice this. Most animals are one gender throughout their lives, but some species are capable of switching. Amphibians, which exhibit several interesting examples of this phenomenon, sometimes change their sex in response to environmental triggers -- which may be social, climactic or chemical in nature. In some circumstances this appears to be historically natural, while others do so as a result of herbicides or other forms of environmental pollution. Factors Determining Gender While chromosomes determine the initial gender of mammals and birds, environmental or epigenetic factors determine the gender of many other animals, including some reptiles, invertebrates and amphibians. Incubation temperatures are often important in determining the initial sex of an animal; but later, social or climactic variables can cause reversals for some species. Some individuals may exhibit traits associated with both genders, which can be an end stage or a step in an active transition between genders. Androgynous Amphibians African reed frogs (Hyperolius viridiflavus) inhabit highly seasonal savannas and form dense breeding colonies during the wet season. In captivity, when kept in all-female populations, some individuals can become fertile and functional males, siring offspring. Some salamanders change sex as well: When scientists tested the responses of crested newt (Triturus cristatus) larvae to extreme temperatures, they found that a percentage of the animals -- which normally differentiate into males or females based on genetic factors -- changed sexes. When the temperatures were at the high end of their acceptable range, about half of the females became male; at lower temperatures, the reverse occurred, and about half of the males became females. This is about animals changing sex. But, notice what happens with Adam. God created man in His image, male and female, but Eve had not yet been created. God blessed man and said " Be fruitful, and multiply, and replenish the earth. Man first had the ability to multiply without a female partner. Then, God explains to man everything that He had created for man's benefit and enjoyment, and given it into the authority of man. God saw everything He had made, judged it to be very good.