It's something which doesn't settle too comfortably with the current science but it's nonetheless reasonably understood --- and to the faithful, we trust that this is how they (and many still) believed it had been accomplished. Allow me to elucidate us:
approximately 6000 years ago:
a). '....the LORD God
formed man of dust from the ground, and breathed into his nostrils the breath of life; and man became a living being. ....'*
b). '....the Lord God
caused the man to fall into a deep sleep; and while he was sleeping, he took one of the man’s ribs and then closed up the place with flesh. Then the Lord God
made a woman from the rib he had taken out of the man, and he brought her to the man. ....'**-
*- Genesis 2
**- Genesis 2
It seems it wasn't beyond Jesus to read this and draw the sort of conclusion most of us would do by simply reading it:
approximately 4000 years later:
c). '...."
Haven't you read," he replied, "that
at the beginning the Creator 'made them male and female,'....'***
***- Matthew 19
some time after Jesus, St. Paul's letters contain the following --- which makes it clear that such beliefs were held to be so in the Early Church:
d). '....So it is written: “The first man Adam became a living being” ; the last Adam, a life-giving spirit. The spiritual did not come first, but the natural, and after that the spiritual.
The first man was of the dust of the earth; the second man is of heaven. As was the earthly man, so are those who are of the earth; and as is the heavenly man, so also are those who are of heaven. And just as we have borne the image of the earthly man, so shall we bear the image of the heavenly man. ....'****
****- 1 Corinthians 15
sometime in 2006 ~ Neil Shubin and his team discovered :
e). Obviously these ( a, b, c & d ) are very ancient ideas and as we learn more about our distant past, we're coming to
understand through both the fossil record and DnA --- that they might have imagined these great events but it's
more likely that we emerged from the oceans. *****/******
*****- (i.e. Tiktaalik -- read Neil Shubin's site:
http://tiktaalik.uchicago.edu/ )
******- '....
Tiktaalik was almost certainly
not our direct ancestor, but a distant cousin......' (
http://pandasthumb.org/archives/2010/01/casey-luskin-em.html : current blogs by PZ Meyers :
http://scienceblogs.com/pharyngula/ )