Evolution in NZ Evolution in NZ Geological Time ScaleGeological Time ScaleSome useful information.Some useful information.Significant Geological Events Significant Geological Events Biological Factors that have Biological Factors that have shaped NZ’s Flora and Fauna.shaped NZ’s Flora and Fauna.

ErasEras EpochsEpochs PeriodsPeriods Age Age (millions of (millions of years)years)

CenozoicCenozoic QuaternaryQuaternary RecentRecent

PleistocenePleistocene0.010.01

1.81.8

TertiaryTertiary PliocenePliocene 55

MioceneMiocene 2323

OligoceneOligocene 3535

EoceneEocene 5757

PaleocenePaleocene 6565

Known as K/T Known as K/T boundaryboundary

MesozoicMesozoic CretaceousCretaceous 144144

JurassicJurassic 206206

The Key Factors that have shaped The Key Factors that have shaped NZ’s Biota are:NZ’s Biota are:

Isolation – NZ has been isolated from other Isolation – NZ has been isolated from other land masses for 65 million years. land masses for 65 million years.

Lack of terrestrial mammals – many of the Lack of terrestrial mammals – many of the niches occupied by mammals in other niches occupied by mammals in other parts of the world have been filled by a parts of the world have been filled by a diversity of birds, insects and reptiles. diversity of birds, insects and reptiles. Lack of mammalian predators has allowed Lack of mammalian predators has allowed species to develop in a way that has ill species to develop in a way that has ill suited them to the influx of humans and suited them to the influx of humans and their mammal associates. their mammal associates.

Size – NZ has a relatively small landmass Size – NZ has a relatively small landmass that at times has been considerably that at times has been considerably smaller. smaller.

There are two basic processes There are two basic processes which explain why a species occurs which explain why a species occurs

in a specific area :in a specific area : DispersalDispersal – a species can move itself to – a species can move itself to

eg NZ on currents, winds, by floating, eg NZ on currents, winds, by floating, flying, on rafts of vegetation. flying, on rafts of vegetation.

VicarianceVicariance -The earth itself can move the -The earth itself can move the species by continental drift. Species that species by continental drift. Species that were present in Gondwanaland when NZ were present in Gondwanaland when NZ drifted away from Australia 80 ma are drifted away from Australia 80 ma are vicariantvicariant groups.groups.

New Zealand’s flora and New Zealand’s flora and fauna (biota) are a fauna (biota) are a

mixture of vicariant and mixture of vicariant and dispersed types.dispersed types.

Organisms present during the Organisms present during the Cretaceous (vicariant groups) Cretaceous (vicariant groups)

DinosaursDinosaurs RatitesRatites WrensWrens TuataraTuatara Frogs (Leiopelma)Frogs (Leiopelma)

Like being on Noah’s Like being on Noah’s Ark! They will drift Ark! They will drift with NZ. They are the with NZ. They are the “Gumboot Gang”“Gumboot Gang”

PeripatusPeripatus Giant Land SnailsGiant Land Snails SkinksSkinks GeckosGeckos BeechesBeeches KaurisKauris PodocarpsPodocarps

Significant Events in Significant Events in NZ’s Geological HistoryNZ’s Geological History

These specific occurrences These specific occurrences have made NZ the unique have made NZ the unique

place it is. place it is.

Gondwana breaks up.Gondwana breaks up.

During the Jurassic Period, Gondwana During the Jurassic Period, Gondwana begins to break apart.begins to break apart.

NZ is connected to Australia and NZ is connected to Australia and Antarctic portions (fully for the first Antarctic portions (fully for the first time) and terrestrial plants and time) and terrestrial plants and animals from Gondwana colonise NZ.animals from Gondwana colonise NZ.

The K/T boundary Mass Extinctions The K/T boundary Mass Extinctions

K/T boundary (Cretaceous/Tertiary) was 65 K/T boundary (Cretaceous/Tertiary) was 65 ma. ma.

An estimated 85% of all living species at An estimated 85% of all living species at the time are wiped out by a mass the time are wiped out by a mass extinction event – probably a massive extinction event – probably a massive asteroid strike. asteroid strike.

This was the end of the Age of Dinosaurs This was the end of the Age of Dinosaurs and the rise of the mammals (and the rise of the mammals (adaptive adaptive radiationradiation into all the empty niches) into all the empty niches)

Losing Australia in the Paleocene! Losing Australia in the Paleocene!

60 ma the Tasman Sea is fully open 60 ma the Tasman Sea is fully open and NZ has geographical isolation and NZ has geographical isolation from Australia.from Australia.

However there are probably not However there are probably not many mammals aboard when NZ many mammals aboard when NZ starts its journey away from starts its journey away from Australia*. Australia*.

Founder Effect.Founder Effect.

*See list of organisms on slide 6*See list of organisms on slide 6

Drowning in the OligoceneDrowning in the Oligocene

35 ma, NZ was reduced to islands 35 ma, NZ was reduced to islands separated by waterways.separated by waterways.

18% of today’s land mass remained. 18% of today’s land mass remained. Habitat was severely depleted, the Habitat was severely depleted, the

temperature was lowered. temperature was lowered. Reduction in genetic diversity had a Reduction in genetic diversity had a

large effect on NZ fauna large effect on NZ fauna The The bottleneck effectbottleneck effect

Making Mountains in the MioceneMaking Mountains in the Miocene

Miocene is 23 – 5 maMiocene is 23 – 5 ma In the mid-Miocene, the Kaikoura In the mid-Miocene, the Kaikoura

Orogeny(mountain building) thrust Orogeny(mountain building) thrust up the Southern Alps, and NZ’s other up the Southern Alps, and NZ’s other mountains. mountains.

Geographic Isolation Geographic Isolation

Freezing in the Pleistocene.Freezing in the Pleistocene.

Ice Ages occurred from 1.8 ma to Ice Ages occurred from 1.8 ma to 14,000 years BP.14,000 years BP.

Cyclical cooling with glaciers Cyclical cooling with glaciers advancing; sea levels dropping and advancing; sea levels dropping and land bridges being created with land bridges being created with offshore islands. offshore islands.

Every 5000 years the interglacial Every 5000 years the interglacial phase caused warmer conditions; phase caused warmer conditions; glaciers retreating; sea levels rising.glaciers retreating; sea levels rising.

What now? What now?

We are in an interglacial at present. We are in an interglacial at present. We also seem to be in the middle of We also seem to be in the middle of

the sixth of the great mass the sixth of the great mass extinctions that have occurred extinctions that have occurred approximately every 100 million approximately every 100 million years since the Cambrian Period. It years since the Cambrian Period. It takes another 5 – 10 million years for takes another 5 – 10 million years for species diversity to recover from species diversity to recover from these mass extinction events. these mass extinction events.

Biological Factors that Biological Factors that have shaped NZ’s have shaped NZ’s Flora and Fauna.Flora and Fauna.

Flowers and PollinationFlowers and Pollination We have no indigenous long-tongued We have no indigenous long-tongued

bee species (social bees) bee species (social bees) Most flowers rely on unspecialised Most flowers rely on unspecialised

agents for pollination so have agents for pollination so have generalised flowers not adapted to generalised flowers not adapted to one specific pollinator. one specific pollinator.

Flowers tend to be small and Flowers tend to be small and unshowy (often white) unshowy (often white)

Pollinators are indigenous Pollinators are indigenous short-tongued bees; some short-tongued bees; some butterflies; some beetles and butterflies; some beetles and moths; flies; birds and bats. moths; flies; birds and bats.

Some plants have specialised:Some plants have specialised:– Wood rose and short tailed batWood rose and short tailed bat– Mistletoe and tuis or bellbirdsMistletoe and tuis or bellbirds– Hebe – some specialised Hebe – some specialised

adaptations for insects.adaptations for insects.– Red flowers for bird pollinators.Red flowers for bird pollinators.

Dioecious PlantsDioecious Plants

Because of the lack of specialised Because of the lack of specialised pollinators, there may be a problem pollinators, there may be a problem with self-fertilisation occurring more with self-fertilisation occurring more than is desirable. than is desirable.

Dioecious plants have male and Dioecious plants have male and female reproductive structures on female reproductive structures on separate plants and so reduce this separate plants and so reduce this problem.problem.

Animal Specialties.Animal Specialties.

Flightlessness conserved energy in Flightlessness conserved energy in cold conditions and could flourish in cold conditions and could flourish in the absence of terrestrial mammal the absence of terrestrial mammal predators.predators.

Gigantism is another adaptive Gigantism is another adaptive feature favouring heat retention.feature favouring heat retention.

Melanism also favours heat retention Melanism also favours heat retention and energy conservation.and energy conservation.

MelanismMelanism

Some NZ birds are dimorphic with a Some NZ birds are dimorphic with a naturally occurring melanic form naturally occurring melanic form within the species. within the species.

The fantail is an example with the The fantail is an example with the melanic form being more common in melanic form being more common in the South Island, bearing out the the South Island, bearing out the heat retention idea.heat retention idea.

FlightlessnessFlightlessness Most common on isolated islands Most common on isolated islands

free of mammalian predators. free of mammalian predators. Significant in Significant in

- Ratites – Moa and Kiwi- Ratites – Moa and Kiwi- Rails – Takahe and WekaRails – Takahe and Weka- Adzebill – now extinct.Adzebill – now extinct.- Wrens – four of the extinct wrens were Wrens – four of the extinct wrens were

flightless.flightless.- Kakapo is the world’s only flightless Kakapo is the world’s only flightless

parrot. parrot. - Weta, earwigs and stick insects also Weta, earwigs and stick insects also

show flightlessness.show flightlessness.

Reduced Reliance on Flight Reduced Reliance on Flight Many of our bird species are weak Many of our bird species are weak

fliers – the wattle birds like Kokako – fliers – the wattle birds like Kokako – blue-wattled crow, Saddle back and blue-wattled crow, Saddle back and Huia (now extinct) Huia (now extinct)

Lesser short-tailed bats (Mystacina Lesser short-tailed bats (Mystacina tuberculata, spend most of their time tuberculata, spend most of their time foraging on the ground. foraging on the ground.

GigantismGigantism Haast’s Eagle, Adzebill, Moa, Haast’s Eagle, Adzebill, Moa,

flightless goose, Sea Eagle – flightless goose, Sea Eagle – all extinct.all extinct.

Takahe, KakapoTakahe, Kakapo Giant invertebrates – wetas.Giant invertebrates – wetas. Once again, this is a Once again, this is a

characteristic that was able characteristic that was able to develop in the absence of to develop in the absence of mammalian predators.mammalian predators.

THE ENDTHE END