Wind dispersion of reproductive cells allowed in seedplants to colonize
land away from water supplies. If water is needed to
passively transport gametes to each other and protect them from desiccation
plants were limited to densely inhabited space near water sources.
Bryophytes & ferns (seedless) are dependent on moist environments
for reproduction but the first seed plants developed an alternate
delivery system allowing independence from water- assisted reproduction.
Conifers produce pollen that can survive by carrying water and
nutrients along. Wind can now carry these male gametophytes to female
gametophytes under the scales of a cone. Fertilization produced a
diploid seed. The seed is protected and can survive dry conditions for a
period of time before growing. Pollen and seeds transferred a conifer’s
water dependence for their reproduction to wind dependence.
